JDK8/Java8源码在线阅读
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package java.awt;
import java.util.Hashtable;
import java.util.Arrays;
/**
* The <code>GridBagLayout</code> class is a flexible layout
* manager that aligns components vertically, horizontally or along their
* baseline without requiring that the components be of the same size.
* Each <code>GridBagLayout</code> object maintains a dynamic,
* rectangular grid of cells, with each component occupying
* one or more cells, called its <em>display area</em>.
* <p>
* Each component managed by a <code>GridBagLayout</code> is associated with
* an instance of {@link GridBagConstraints}. The constraints object
* specifies where a component's display area should be located on the grid
* and how the component should be positioned within its display area. In
* addition to its constraints object, the <code>GridBagLayout</code> also
* considers each component's minimum and preferred sizes in order to
* determine a component's size.
* <p>
* The overall orientation of the grid depends on the container's
* {@link ComponentOrientation} property. For horizontal left-to-right
* orientations, grid coordinate (0,0) is in the upper left corner of the
* container with x increasing to the right and y increasing downward. For
* horizontal right-to-left orientations, grid coordinate (0,0) is in the upper
* right corner of the container with x increasing to the left and y
* increasing downward.
* <p>
* To use a grid bag layout effectively, you must customize one or more
* of the <code>GridBagConstraints</code> objects that are associated
* with its components. You customize a <code>GridBagConstraints</code>
* object by setting one or more of its instance variables:
*
* <dl>
* <dt>{@link GridBagConstraints#gridx},
* {@link GridBagConstraints#gridy}
* <dd>Specifies the cell containing the leading corner of the component's
* display area, where the cell at the origin of the grid has address
* <code>gridx = 0</code>,
* <code>gridy = 0</code>. For horizontal left-to-right layout,
* a component's leading corner is its upper left. For horizontal
* right-to-left layout, a component's leading corner is its upper right.
* Use <code>GridBagConstraints.RELATIVE</code> (the default value)
* to specify that the component be placed immediately following
* (along the x axis for <code>gridx</code> or the y axis for
* <code>gridy</code>) the component that was added to the container
* just before this component was added.
* <dt>{@link GridBagConstraints#gridwidth},
* {@link GridBagConstraints#gridheight}
* <dd>Specifies the number of cells in a row (for <code>gridwidth</code>)
* or column (for <code>gridheight</code>)
* in the component's display area.
* The default value is 1.
* Use <code>GridBagConstraints.REMAINDER</code> to specify
* that the component's display area will be from <code>gridx</code>
* to the last cell in the row (for <code>gridwidth</code>)
* or from <code>gridy</code> to the last cell in the column
* (for <code>gridheight</code>).
*
* Use <code>GridBagConstraints.RELATIVE</code> to specify
* that the component's display area will be from <code>gridx</code>
* to the next to the last cell in its row (for <code>gridwidth</code>
* or from <code>gridy</code> to the next to the last cell in its
* column (for <code>gridheight</code>).
*
* <dt>{@link GridBagConstraints#fill}
* <dd>Used when the component's display area
* is larger than the component's requested size
* to determine whether (and how) to resize the component.
* Possible values are
* <code>GridBagConstraints.NONE</code> (the default),
* <code>GridBagConstraints.HORIZONTAL</code>
* (make the component wide enough to fill its display area
* horizontally, but don't change its height),
* <code>GridBagConstraints.VERTICAL</code>
* (make the component tall enough to fill its display area
* vertically, but don't change its width), and
* <code>GridBagConstraints.BOTH</code>
* (make the component fill its display area entirely).
* <dt>{@link GridBagConstraints#ipadx},
* {@link GridBagConstraints#ipady}
* <dd>Specifies the component's internal padding within the layout,
* how much to add to the minimum size of the component.
* The width of the component will be at least its minimum width
* plus <code>ipadx</code> pixels. Similarly, the height of
* the component will be at least the minimum height plus
* <code>ipady</code> pixels.
* <dt>{@link GridBagConstraints#insets}
* <dd>Specifies the component's external padding, the minimum
* amount of space between the component and the edges of its display area.
* <dt>{@link GridBagConstraints#anchor}
* <dd>Specifies where the component should be positioned in its display area.
* There are three kinds of possible values: absolute, orientation-relative,
* and baseline-relative
* Orientation relative values are interpreted relative to the container's
* <code>ComponentOrientation</code> property while absolute values
* are not. Baseline relative values are calculated relative to the
* baseline. Valid values are:
*
* <center><table BORDER=0 WIDTH=800
* SUMMARY="absolute, relative and baseline values as described above">
* <tr>
* <th><P style="text-align:left">Absolute Values</th>
* <th><P style="text-align:left">Orientation Relative Values</th>
* <th><P style="text-align:left">Baseline Relative Values</th>
* </tr>
* <tr>
* <td>
* <ul style="list-style-type:none">
* <li><code>GridBagConstraints.NORTH</code></li>
* <li><code>GridBagConstraints.SOUTH</code></li>
* <li><code>GridBagConstraints.WEST</code></li>
* <li><code>GridBagConstraints.EAST</code></li>
* <li><code>GridBagConstraints.NORTHWEST</code></li>
* <li><code>GridBagConstraints.NORTHEAST</code></li>
* <li><code>GridBagConstraints.SOUTHWEST</code></li>
* <li><code>GridBagConstraints.SOUTHEAST</code></li>
* <li><code>GridBagConstraints.CENTER</code> (the default)</li>
* </ul>
* </td>
* <td>
* <ul style="list-style-type:none">
* <li><code>GridBagConstraints.PAGE_START</code></li>
* <li><code>GridBagConstraints.PAGE_END</code></li>
* <li><code>GridBagConstraints.LINE_START</code></li>
* <li><code>GridBagConstraints.LINE_END</code></li>
* <li><code>GridBagConstraints.FIRST_LINE_START</code></li>
* <li><code>GridBagConstraints.FIRST_LINE_END</code></li>
* <li><code>GridBagConstraints.LAST_LINE_START</code></li>
* <li><code>GridBagConstraints.LAST_LINE_END</code></li>
* </ul>
* </td>
* <td>
* <ul style="list-style-type:none">
* <li><code>GridBagConstraints.BASELINE</code></li>
* <li><code>GridBagConstraints.BASELINE_LEADING</code></li>
* <li><code>GridBagConstraints.BASELINE_TRAILING</code></li>
* <li><code>GridBagConstraints.ABOVE_BASELINE</code></li>
* <li><code>GridBagConstraints.ABOVE_BASELINE_LEADING</code></li>
* <li><code>GridBagConstraints.ABOVE_BASELINE_TRAILING</code></li>
* <li><code>GridBagConstraints.BELOW_BASELINE</code></li>
* <li><code>GridBagConstraints.BELOW_BASELINE_LEADING</code></li>
* <li><code>GridBagConstraints.BELOW_BASELINE_TRAILING</code></li>
* </ul>
* </td>
* </tr>
* </table></center>
* <dt>{@link GridBagConstraints#weightx},
* {@link GridBagConstraints#weighty}
* <dd>Used to determine how to distribute space, which is
* important for specifying resizing behavior.
* Unless you specify a weight for at least one component
* in a row (<code>weightx</code>) and column (<code>weighty</code>),
* all the components clump together in the center of their container.
* This is because when the weight is zero (the default),
* the <code>GridBagLayout</code> object puts any extra space
* between its grid of cells and the edges of the container.
* </dl>
* <p>
* Each row may have a baseline; the baseline is determined by the
* components in that row that have a valid baseline and are aligned
* along the baseline (the component's anchor value is one of {@code
* BASELINE}, {@code BASELINE_LEADING} or {@code BASELINE_TRAILING}).
* If none of the components in the row has a valid baseline, the row
* does not have a baseline.
* <p>
* If a component spans rows it is aligned either to the baseline of
* the start row (if the baseline-resize behavior is {@code
* CONSTANT_ASCENT}) or the end row (if the baseline-resize behavior
* is {@code CONSTANT_DESCENT}). The row that the component is
* aligned to is called the <em>prevailing row</em>.
* <p>
* The following figure shows a baseline layout and includes a
* component that spans rows:
* <center><table summary="Baseline Layout">
* <tr ALIGN=CENTER>
* <td>
* <img src="doc-files/GridBagLayout-baseline.png"
* alt="The following text describes this graphic (Figure 1)." style="float:center">
* </td>
* </table></center>
* This layout consists of three components:
* <ul><li>A panel that starts in row 0 and ends in row 1. The panel
* has a baseline-resize behavior of <code>CONSTANT_DESCENT</code> and has
* an anchor of <code>BASELINE</code>. As the baseline-resize behavior
* is <code>CONSTANT_DESCENT</code> the prevailing row for the panel is
* row 1.
* <li>Two buttons, each with a baseline-resize behavior of
* <code>CENTER_OFFSET</code> and an anchor of <code>BASELINE</code>.
* </ul>
* Because the second button and the panel share the same prevailing row,
* they are both aligned along their baseline.
* <p>
* Components positioned using one of the baseline-relative values resize
* differently than when positioned using an absolute or orientation-relative
* value. How components change is dictated by how the baseline of the
* prevailing row changes. The baseline is anchored to the
* bottom of the display area if any components with the same prevailing row
* have a baseline-resize behavior of <code>CONSTANT_DESCENT</code>,
* otherwise the baseline is anchored to the top of the display area.
* The following rules dictate the resize behavior:
* <ul>
* <li>Resizable components positioned above the baseline can only
* grow as tall as the baseline. For example, if the baseline is at 100
* and anchored at the top, a resizable component positioned above the
* baseline can never grow more than 100 units.
* <li>Similarly, resizable components positioned below the baseline can
* only grow as high as the difference between the display height and the
* baseline.
* <li>Resizable components positioned on the baseline with a
* baseline-resize behavior of <code>OTHER</code> are only resized if
* the baseline at the resized size fits within the display area. If
* the baseline is such that it does not fit within the display area
* the component is not resized.
* <li>Components positioned on the baseline that do not have a
* baseline-resize behavior of <code>OTHER</code>
* can only grow as tall as {@code display height - baseline + baseline of component}.
* </ul>
* If you position a component along the baseline, but the
* component does not have a valid baseline, it will be vertically centered
* in its space. Similarly if you have positioned a component relative
* to the baseline and none of the components in the row have a valid
* baseline the component is vertically centered.
* <p>
* The following figures show ten components (all buttons)
* managed by a grid bag layout. Figure 2 shows the layout for a horizontal,
* left-to-right container and Figure 3 shows the layout for a horizontal,
* right-to-left container.
*
* <center><table WIDTH=600 summary="layout">
* <tr ALIGN=CENTER>
* <td>
* <img src="doc-files/GridBagLayout-1.gif" alt="The preceding text describes this graphic (Figure 1)." style="float:center; margin: 7px 10px;">
* </td>
* <td>
* <img src="doc-files/GridBagLayout-2.gif" alt="The preceding text describes this graphic (Figure 2)." style="float:center; margin: 7px 10px;">
* </td>
* <tr ALIGN=CENTER>
* <td>Figure 2: Horizontal, Left-to-Right</td>
* <td>Figure 3: Horizontal, Right-to-Left</td>
* </tr>
* </table></center>
* <p>
* Each of the ten components has the <code>fill</code> field
* of its associated <code>GridBagConstraints</code> object
* set to <code>GridBagConstraints.BOTH</code>.
* In addition, the components have the following non-default constraints:
*
* <ul>
* <li>Button1, Button2, Button3: <code>weightx = 1.0</code>
* <li>Button4: <code>weightx = 1.0</code>,
* <code>gridwidth = GridBagConstraints.REMAINDER</code>
* <li>Button5: <code>gridwidth = GridBagConstraints.REMAINDER</code>
* <li>Button6: <code>gridwidth = GridBagConstraints.RELATIVE</code>
* <li>Button7: <code>gridwidth = GridBagConstraints.REMAINDER</code>
* <li>Button8: <code>gridheight = 2</code>,
* <code>weighty = 1.0</code>
* <li>Button9, Button 10:
* <code>gridwidth = GridBagConstraints.REMAINDER</code>
* </ul>
* <p>
* Here is the code that implements the example shown above:
*
* <hr><blockquote><pre>
* import java.awt.*;
* import java.util.*;
* import java.applet.Applet;
*
* public class GridBagEx1 extends Applet {
*
* protected void makebutton(String name,
* GridBagLayout gridbag,
* GridBagConstraints c) {
* Button button = new Button(name);
* gridbag.setConstraints(button, c);
* add(button);
* }
*
* public void init() {
* GridBagLayout gridbag = new GridBagLayout();
* GridBagConstraints c = new GridBagConstraints();
*
* setFont(new Font("SansSerif", Font.PLAIN, 14));
* setLayout(gridbag);
*
* c.fill = GridBagConstraints.BOTH;
* c.weightx = 1.0;
* makebutton("Button1", gridbag, c);
* makebutton("Button2", gridbag, c);
* makebutton("Button3", gridbag, c);
*
* c.gridwidth = GridBagConstraints.REMAINDER; //end row
* makebutton("Button4", gridbag, c);
*
* c.weightx = 0.0; //reset to the default
* makebutton("Button5", gridbag, c); //another row
*
* c.gridwidth = GridBagConstraints.RELATIVE; //next-to-last in row
* makebutton("Button6", gridbag, c);
*
* c.gridwidth = GridBagConstraints.REMAINDER; //end row
* makebutton("Button7", gridbag, c);
*
* c.gridwidth = 1; //reset to the default
* c.gridheight = 2;
* c.weighty = 1.0;
* makebutton("Button8", gridbag, c);
*
* c.weighty = 0.0; //reset to the default
* c.gridwidth = GridBagConstraints.REMAINDER; //end row
* c.gridheight = 1; //reset to the default
* makebutton("Button9", gridbag, c);
* makebutton("Button10", gridbag, c);
*
* setSize(300, 100);
* }
*
* public static void main(String args[]) {
* Frame f = new Frame("GridBag Layout Example");
* GridBagEx1 ex1 = new GridBagEx1();
*
* ex1.init();
*
* f.add("Center", ex1);
* f.pack();
* f.setSize(f.getPreferredSize());
* f.show();
* }
* }
* </pre></blockquote><hr>
* <p>
* @author Doug Stein
* @author Bill Spitzak (orignial NeWS & OLIT implementation)
* @see java.awt.GridBagConstraints
* @see java.awt.GridBagLayoutInfo
* @see java.awt.ComponentOrientation
* @since JDK1.0
*/
public class GridBagLayout implements LayoutManager2,
java.io.Serializable {
static final int EMPIRICMULTIPLIER = 2;
/**
* This field is no longer used to reserve arrays and kept for backward
* compatibility. Previously, this was
* the maximum number of grid positions (both horizontal and
* vertical) that could be laid out by the grid bag layout.
* Current implementation doesn't impose any limits
* on the size of a grid.
*/
protected static final int MAXGRIDSIZE = 512;
/**
* The smallest grid that can be laid out by the grid bag layout.
*/
protected static final int MINSIZE = 1;
/**
* The preferred grid size that can be laid out by the grid bag layout.
*/
protected static final int PREFERREDSIZE = 2;
/**
* This hashtable maintains the association between
* a component and its gridbag constraints.
* The Keys in <code>comptable</code> are the components and the
* values are the instances of <code>GridBagConstraints</code>.
*
* @serial
* @see java.awt.GridBagConstraints
*/
protected Hashtable<Component,GridBagConstraints> comptable;
/**
* This field holds a gridbag constraints instance
* containing the default values, so if a component
* does not have gridbag constraints associated with
* it, then the component will be assigned a
* copy of the <code>defaultConstraints</code>.
*
* @serial
* @see #getConstraints(Component)
* @see #setConstraints(Component, GridBagConstraints)
* @see #lookupConstraints(Component)
*/
protected GridBagConstraints defaultConstraints;
/**
* This field holds the layout information
* for the gridbag. The information in this field
* is based on the most recent validation of the
* gridbag.
* If <code>layoutInfo</code> is <code>null</code>
* this indicates that there are no components in
* the gridbag or if there are components, they have
* not yet been validated.
*
* @serial
* @see #getLayoutInfo(Container, int)
*/
protected GridBagLayoutInfo layoutInfo;
/**
* This field holds the overrides to the column minimum
* width. If this field is non-<code>null</code> the values are
* applied to the gridbag after all of the minimum columns
* widths have been calculated.
* If columnWidths has more elements than the number of
* columns, columns are added to the gridbag to match
* the number of elements in columnWidth.
*
* @serial
* @see #getLayoutDimensions()
*/
public int columnWidths[];
/**
* This field holds the overrides to the row minimum
* heights. If this field is non-<code>null</code> the values are
* applied to the gridbag after all of the minimum row
* heights have been calculated.
* If <code>rowHeights</code> has more elements than the number of
* rows, rows are added to the gridbag to match
* the number of elements in <code>rowHeights</code>.
*
* @serial
* @see #getLayoutDimensions()
*/
public int rowHeights[];
/**
* This field holds the overrides to the column weights.
* If this field is non-<code>null</code> the values are
* applied to the gridbag after all of the columns
* weights have been calculated.
* If <code>columnWeights[i]</code> > weight for column i, then
* column i is assigned the weight in <code>columnWeights[i]</code>.
* If <code>columnWeights</code> has more elements than the number
* of columns, the excess elements are ignored - they do
* not cause more columns to be created.
*
* @serial
*/
public double columnWeights[];
/**
* This field holds the overrides to the row weights.
* If this field is non-<code>null</code> the values are
* applied to the gridbag after all of the rows
* weights have been calculated.
* If <code>rowWeights[i]</code> > weight for row i, then
* row i is assigned the weight in <code>rowWeights[i]</code>.
* If <code>rowWeights</code> has more elements than the number
* of rows, the excess elements are ignored - they do
* not cause more rows to be created.
*
* @serial
*/
public double rowWeights[];
/**
* The component being positioned. This is set before calling into
* <code>adjustForGravity</code>.
*/
private Component componentAdjusting;
/**
* Creates a grid bag layout manager.
*/
public GridBagLayout () {
comptable = new Hashtable<Component,GridBagConstraints>();
defaultConstraints = new GridBagConstraints();
}
/**
* Sets the constraints for the specified component in this layout.
* @param comp the component to be modified
* @param constraints the constraints to be applied
*/
public void setConstraints(Component comp, GridBagConstraints constraints) {
comptable.put(comp, (GridBagConstraints)constraints.clone());
}
/**
* Gets the constraints for the specified component. A copy of
* the actual <code>GridBagConstraints</code> object is returned.
* @param comp the component to be queried
* @return the constraint for the specified component in this
* grid bag layout; a copy of the actual constraint
* object is returned
*/
public GridBagConstraints getConstraints(Component comp) {
GridBagConstraints constraints = comptable.get(comp);
if (constraints == null) {
setConstraints(comp, defaultConstraints);
constraints = comptable.get(comp);
}
return (GridBagConstraints)constraints.clone();
}
/**
* Retrieves the constraints for the specified component.
* The return value is not a copy, but is the actual
* <code>GridBagConstraints</code> object used by the layout mechanism.
* <p>
* If <code>comp</code> is not in the <code>GridBagLayout</code>,
* a set of default <code>GridBagConstraints</code> are returned.
* A <code>comp</code> value of <code>null</code> is invalid
* and returns <code>null</code>.
*
* @param comp the component to be queried
* @return the constraints for the specified component
*/
protected GridBagConstraints lookupConstraints(Component comp) {
GridBagConstraints constraints = comptable.get(comp);
if (constraints == null) {
setConstraints(comp, defaultConstraints);
constraints = comptable.get(comp);
}
return constraints;
}
/**
* Removes the constraints for the specified component in this layout
* @param comp the component to be modified
*/
private void removeConstraints(Component comp) {
comptable.remove(comp);
}
/**
* Determines the origin of the layout area, in the graphics coordinate
* space of the target container. This value represents the pixel
* coordinates of the top-left corner of the layout area regardless of
* the <code>ComponentOrientation</code> value of the container. This
* is distinct from the grid origin given by the cell coordinates (0,0).
* Most applications do not call this method directly.
* @return the graphics origin of the cell in the top-left
* corner of the layout grid
* @see java.awt.ComponentOrientation
* @since JDK1.1
*/
public Point getLayoutOrigin () {
Point origin = new Point(0,0);
if (layoutInfo != null) {
origin.x = layoutInfo.startx;
origin.y = layoutInfo.starty;
}
return origin;
}
/**
* Determines column widths and row heights for the layout grid.
* <p>
* Most applications do not call this method directly.
* @return an array of two arrays, containing the widths
* of the layout columns and
* the heights of the layout rows
* @since JDK1.1
*/
public int [][] getLayoutDimensions () {
if (layoutInfo == null)
return new int[2][0];
int dim[][] = new int [2][];
dim[0] = new int[layoutInfo.width];
dim[1] = new int[layoutInfo.height];
System.arraycopy(layoutInfo.minWidth, 0, dim[0], 0, layoutInfo.width);
System.arraycopy(layoutInfo.minHeight, 0, dim[1], 0, layoutInfo.height);
return dim;
}
/**
* Determines the weights of the layout grid's columns and rows.
* Weights are used to calculate how much a given column or row
* stretches beyond its preferred size, if the layout has extra
* room to fill.
* <p>
* Most applications do not call this method directly.
* @return an array of two arrays, representing the
* horizontal weights of the layout columns
* and the vertical weights of the layout rows
* @since JDK1.1
*/
public double [][] getLayoutWeights () {
if (layoutInfo == null)
return new double[2][0];
double weights[][] = new double [2][];
weights[0] = new double[layoutInfo.width];
weights[1] = new double[layoutInfo.height];
System.arraycopy(layoutInfo.weightX, 0, weights[0], 0, layoutInfo.width);
System.arraycopy(layoutInfo.weightY, 0, weights[1], 0, layoutInfo.height);
return weights;
}
/**
* Determines which cell in the layout grid contains the point
* specified by <code>(x, y)</code>. Each cell is identified
* by its column index (ranging from 0 to the number of columns
* minus 1) and its row index (ranging from 0 to the number of
* rows minus 1).
* <p>
* If the <code>(x, y)</code> point lies
* outside the grid, the following rules are used.
* The column index is returned as zero if <code>x</code> lies to the
* left of the layout for a left-to-right container or to the right of
* the layout for a right-to-left container. The column index is returned
* as the number of columns if <code>x</code> lies
* to the right of the layout in a left-to-right container or to the left
* in a right-to-left container.
* The row index is returned as zero if <code>y</code> lies above the
* layout, and as the number of rows if <code>y</code> lies
* below the layout. The orientation of a container is determined by its
* <code>ComponentOrientation</code> property.
* @param x the <i>x</i> coordinate of a point
* @param y the <i>y</i> coordinate of a point
* @return an ordered pair of indexes that indicate which cell
* in the layout grid contains the point
* (<i>x</i>, <i>y</i>).
* @see java.awt.ComponentOrientation
* @since JDK1.1
*/
public Point location(int x, int y) {
Point loc = new Point(0,0);
int i, d;
if (layoutInfo == null)
return loc;
d = layoutInfo.startx;
if (!rightToLeft) {
for (i=0; i<layoutInfo.width; i++) {
d += layoutInfo.minWidth[i];
if (d > x)
break;
}
} else {
for (i=layoutInfo.width-1; i>=0; i--) {
if (d > x)
break;
d += layoutInfo.minWidth[i];
}
i++;
}
loc.x = i;
d = layoutInfo.starty;
for (i=0; i<layoutInfo.height; i++) {
d += layoutInfo.minHeight[i];
if (d > y)
break;
}
loc.y = i;
return loc;
}
/**
* Has no effect, since this layout manager does not use a per-component string.
*/
public void addLayoutComponent(String name, Component comp) {
}
/**
* Adds the specified component to the layout, using the specified
* <code>constraints</code> object. Note that constraints
* are mutable and are, therefore, cloned when cached.
*
* @param comp the component to be added
* @param constraints an object that determines how
* the component is added to the layout
* @exception IllegalArgumentException if <code>constraints</code>
* is not a <code>GridBagConstraint</code>
*/
public void addLayoutComponent(Component comp, Object constraints) {
if (constraints instanceof GridBagConstraints) {
setConstraints(comp, (GridBagConstraints)constraints);
} else if (constraints != null) {
throw new IllegalArgumentException("cannot add to layout: constraints must be a GridBagConstraint");
}
}
/**
* Removes the specified component from this layout.
* <p>
* Most applications do not call this method directly.
* @param comp the component to be removed.
* @see java.awt.Container#remove(java.awt.Component)
* @see java.awt.Container#removeAll()
*/
public void removeLayoutComponent(Component comp) {
removeConstraints(comp);
}
/**
* Determines the preferred size of the <code>parent</code>
* container using this grid bag layout.
* <p>
* Most applications do not call this method directly.
*
* @param parent the container in which to do the layout
* @see java.awt.Container#getPreferredSize
* @return the preferred size of the <code>parent</code>
* container
*/
public Dimension preferredLayoutSize(Container parent) {
GridBagLayoutInfo info = getLayoutInfo(parent, PREFERREDSIZE);
return getMinSize(parent, info);
}
/**
* Determines the minimum size of the <code>parent</code> container
* using this grid bag layout.
* <p>
* Most applications do not call this method directly.
* @param parent the container in which to do the layout
* @see java.awt.Container#doLayout
* @return the minimum size of the <code>parent</code> container
*/
public Dimension minimumLayoutSize(Container parent) {
GridBagLayoutInfo info = getLayoutInfo(parent, MINSIZE);
return getMinSize(parent, info);
}
/**
* Returns the maximum dimensions for this layout given the components
* in the specified target container.
* @param target the container which needs to be laid out
* @see Container
* @see #minimumLayoutSize(Container)
* @see #preferredLayoutSize(Container)
* @return the maximum dimensions for this layout
*/
public Dimension maximumLayoutSize(Container target) {
return new Dimension(Integer.MAX_VALUE, Integer.MAX_VALUE);
}
/**
* Returns the alignment along the x axis. This specifies how
* the component would like to be aligned relative to other
* components. The value should be a number between 0 and 1
* where 0 represents alignment along the origin, 1 is aligned
* the furthest away from the origin, 0.5 is centered, etc.
* <p>
* @return the value <code>0.5f</code> to indicate centered
*/
public float getLayoutAlignmentX(Container parent) {
return 0.5f;
}
/**
* Returns the alignment along the y axis. This specifies how
* the component would like to be aligned relative to other
* components. The value should be a number between 0 and 1
* where 0 represents alignment along the origin, 1 is aligned
* the furthest away from the origin, 0.5 is centered, etc.
* <p>
* @return the value <code>0.5f</code> to indicate centered
*/
public float getLayoutAlignmentY(Container parent) {
return 0.5f;
}
/**
* Invalidates the layout, indicating that if the layout manager
* has cached information it should be discarded.
*/
public void invalidateLayout(Container target) {
}
/**
* Lays out the specified container using this grid bag layout.
* This method reshapes components in the specified container in
* order to satisfy the constraints of this <code>GridBagLayout</code>
* object.
* <p>
* Most applications do not call this method directly.
* @param parent the container in which to do the layout
* @see java.awt.Container
* @see java.awt.Container#doLayout
*/
public void layoutContainer(Container parent) {
arrangeGrid(parent);
}
/**
* Returns a string representation of this grid bag layout's values.
* @return a string representation of this grid bag layout.
*/
public String toString() {
return getClass().getName();
}
/**
* Print the layout information. Useful for debugging.
*/
/* DEBUG
*
* protected void dumpLayoutInfo(GridBagLayoutInfo s) {
* int x;
*
* System.out.println("Col\tWidth\tWeight");
* for (x=0; x<s.width; x++) {
* System.out.println(x + "\t" +
* s.minWidth[x] + "\t" +
* s.weightX[x]);
* }
* System.out.println("Row\tHeight\tWeight");
* for (x=0; x<s.height; x++) {
* System.out.println(x + "\t" +
* s.minHeight[x] + "\t" +
* s.weightY[x]);
* }
* }
*/
/**
* Print the layout constraints. Useful for debugging.
*/
/* DEBUG
*
* protected void dumpConstraints(GridBagConstraints constraints) {
* System.out.println(
* "wt " +
* constraints.weightx +
* " " +
* constraints.weighty +
* ", " +
*
* "box " +
* constraints.gridx +
* " " +
* constraints.gridy +
* " " +
* constraints.gridwidth +
* " " +
* constraints.gridheight +
* ", " +
*
* "min " +
* constraints.minWidth +
* " " +
* constraints.minHeight +
* ", " +
*
* "pad " +
* constraints.insets.bottom +
* " " +
* constraints.insets.left +
* " " +
* constraints.insets.right +
* " " +
* constraints.insets.top +
* " " +
* constraints.ipadx +
* " " +
* constraints.ipady);
* }
*/
/**
* Fills in an instance of <code>GridBagLayoutInfo</code> for the
* current set of managed children. This requires three passes through the
* set of children:
*
* <ol>
* <li>Figure out the dimensions of the layout grid.
* <li>Determine which cells the components occupy.
* <li>Distribute the weights and min sizes among the rows/columns.
* </ol>
*
* This also caches the minsizes for all the children when they are
* first encountered (so subsequent loops don't need to ask again).
* <p>
* This method should only be used internally by
* <code>GridBagLayout</code>.
*
* @param parent the layout container
* @param sizeflag either <code>PREFERREDSIZE</code> or
* <code>MINSIZE</code>
* @return the <code>GridBagLayoutInfo</code> for the set of children
* @since 1.4
*/
protected GridBagLayoutInfo getLayoutInfo(Container parent, int sizeflag) {
return GetLayoutInfo(parent, sizeflag);
}
/*
* Calculate maximum array sizes to allocate arrays without ensureCapacity
* we may use preCalculated sizes in whole class because of upper estimation of
* maximumArrayXIndex and maximumArrayYIndex.
*/
private long[] preInitMaximumArraySizes(Container parent){
Component components[] = parent.getComponents();
Component comp;
GridBagConstraints constraints;
int curX, curY;
int curWidth, curHeight;
int preMaximumArrayXIndex = 0;
int preMaximumArrayYIndex = 0;
long [] returnArray = new long[2];
for (int compId = 0 ; compId < components.length ; compId++) {
comp = components[compId];
if (!comp.isVisible()) {
continue;
}
constraints = lookupConstraints(comp);
curX = constraints.gridx;
curY = constraints.gridy;
curWidth = constraints.gridwidth;
curHeight = constraints.gridheight;
// -1==RELATIVE, means that column|row equals to previously added component,
// since each next Component with gridx|gridy == RELATIVE starts from
// previous position, so we should start from previous component which
// already used in maximumArray[X|Y]Index calculation. We could just increase
// maximum by 1 to handle situation when component with gridx=-1 was added.
if (curX < 0){
curX = ++preMaximumArrayYIndex;
}
if (curY < 0){
curY = ++preMaximumArrayXIndex;
}
// gridwidth|gridheight may be equal to RELATIVE (-1) or REMAINDER (0)
// in any case using 1 instead of 0 or -1 should be sufficient to for
// correct maximumArraySizes calculation
if (curWidth <= 0){
curWidth = 1;
}
if (curHeight <= 0){
curHeight = 1;
}
preMaximumArrayXIndex = Math.max(curY + curHeight, preMaximumArrayXIndex);
preMaximumArrayYIndex = Math.max(curX + curWidth, preMaximumArrayYIndex);
} //for (components) loop
// Must specify index++ to allocate well-working arrays.
/* fix for 4623196.
* now return long array instead of Point
*/
returnArray[0] = preMaximumArrayXIndex;
returnArray[1] = preMaximumArrayYIndex;
return returnArray;
} //PreInitMaximumSizes
/**
* This method is obsolete and supplied for backwards
* compatibility only; new code should call {@link
* #getLayoutInfo(java.awt.Container, int) getLayoutInfo} instead.
* This method is the same as <code>getLayoutInfo</code>;
* refer to <code>getLayoutInfo</code> for details on parameters
* and return value.
*/
protected GridBagLayoutInfo GetLayoutInfo(Container parent, int sizeflag) {
synchronized (parent.getTreeLock()) {
GridBagLayoutInfo r;
Component comp;
GridBagConstraints constraints;
Dimension d;
Component components[] = parent.getComponents();
// Code below will address index curX+curWidth in the case of yMaxArray, weightY
// ( respectively curY+curHeight for xMaxArray, weightX ) where
// curX in 0 to preInitMaximumArraySizes.y
// Thus, the maximum index that could
// be calculated in the following code is curX+curX.
// EmpericMultier equals 2 because of this.
int layoutWidth, layoutHeight;
int []xMaxArray;
int []yMaxArray;
int compindex, i, k, px, py, pixels_diff, nextSize;
int curX = 0; // constraints.gridx
int curY = 0; // constraints.gridy
int curWidth = 1; // constraints.gridwidth
int curHeight = 1; // constraints.gridheight
int curRow, curCol;
double weight_diff, weight;
int maximumArrayXIndex = 0;
int maximumArrayYIndex = 0;
int anchor;
/*
* Pass #1
*
* Figure out the dimensions of the layout grid (use a value of 1 for
* zero or negative widths and heights).
*/
layoutWidth = layoutHeight = 0;
curRow = curCol = -1;
long [] arraySizes = preInitMaximumArraySizes(parent);
/* fix for 4623196.
* If user try to create a very big grid we can
* get NegativeArraySizeException because of integer value
* overflow (EMPIRICMULTIPLIER*gridSize might be more then Integer.MAX_VALUE).
* We need to detect this situation and try to create a
* grid with Integer.MAX_VALUE size instead.
*/
maximumArrayXIndex = (EMPIRICMULTIPLIER * arraySizes[0] > Integer.MAX_VALUE )? Integer.MAX_VALUE : EMPIRICMULTIPLIER*(int)arraySizes[0];
maximumArrayYIndex = (EMPIRICMULTIPLIER * arraySizes[1] > Integer.MAX_VALUE )? Integer.MAX_VALUE : EMPIRICMULTIPLIER*(int)arraySizes[1];
if (rowHeights != null){
maximumArrayXIndex = Math.max(maximumArrayXIndex, rowHeights.length);
}
if (columnWidths != null){
maximumArrayYIndex = Math.max(maximumArrayYIndex, columnWidths.length);
}
xMaxArray = new int[maximumArrayXIndex];
yMaxArray = new int[maximumArrayYIndex];
boolean hasBaseline = false;
for (compindex = 0 ; compindex < components.length ; compindex++) {
comp = components[compindex];
if (!comp.isVisible())
continue;
constraints = lookupConstraints(comp);
curX = constraints.gridx;
curY = constraints.gridy;
curWidth = constraints.gridwidth;
if (curWidth <= 0)
curWidth = 1;
curHeight = constraints.gridheight;
if (curHeight <= 0)
curHeight = 1;
/* If x or y is negative, then use relative positioning: */
if (curX < 0 && curY < 0) {
if (curRow >= 0)
curY = curRow;
else if (curCol >= 0)
curX = curCol;
else
curY = 0;
}
if (curX < 0) {
px = 0;
for (i = curY; i < (curY + curHeight); i++) {
px = Math.max(px, xMaxArray[i]);
}
curX = px - curX - 1;
if(curX < 0)
curX = 0;
}
else if (curY < 0) {
py = 0;
for (i = curX; i < (curX + curWidth); i++) {
py = Math.max(py, yMaxArray[i]);
}
curY = py - curY - 1;
if(curY < 0)
curY = 0;
}
/* Adjust the grid width and height
* fix for 5005945: unneccessary loops removed
*/
px = curX + curWidth;
if (layoutWidth < px) {
layoutWidth = px;
}
py = curY + curHeight;
if (layoutHeight < py) {
layoutHeight = py;
}
/* Adjust xMaxArray and yMaxArray */
for (i = curX; i < (curX + curWidth); i++) {
yMaxArray[i] =py;
}
for (i = curY; i < (curY + curHeight); i++) {
xMaxArray[i] = px;
}
/* Cache the current slave's size. */
if (sizeflag == PREFERREDSIZE)
d = comp.getPreferredSize();
else
d = comp.getMinimumSize();
constraints.minWidth = d.width;
constraints.minHeight = d.height;
if (calculateBaseline(comp, constraints, d)) {
hasBaseline = true;
}
/* Zero width and height must mean that this is the last item (or
* else something is wrong). */
if (constraints.gridheight == 0 && constraints.gridwidth == 0)
curRow = curCol = -1;
/* Zero width starts a new row */
if (constraints.gridheight == 0 && curRow < 0)
curCol = curX + curWidth;
/* Zero height starts a new column */
else if (constraints.gridwidth == 0 && curCol < 0)
curRow = curY + curHeight;
} //for (components) loop
/*
* Apply minimum row/column dimensions
*/
if (columnWidths != null && layoutWidth < columnWidths.length)
layoutWidth = columnWidths.length;
if (rowHeights != null && layoutHeight < rowHeights.length)
layoutHeight = rowHeights.length;
r = new GridBagLayoutInfo(layoutWidth, layoutHeight);
/*
* Pass #2
*
* Negative values for gridX are filled in with the current x value.
* Negative values for gridY are filled in with the current y value.
* Negative or zero values for gridWidth and gridHeight end the current
* row or column, respectively.
*/
curRow = curCol = -1;
Arrays.fill(xMaxArray, 0);
Arrays.fill(yMaxArray, 0);
int[] maxAscent = null;
int[] maxDescent = null;
short[] baselineType = null;
if (hasBaseline) {
r.maxAscent = maxAscent = new int[layoutHeight];
r.maxDescent = maxDescent = new int[layoutHeight];
r.baselineType = baselineType = new short[layoutHeight];
r.hasBaseline = true;
}
for (compindex = 0 ; compindex < components.length ; compindex++) {
comp = components[compindex];
if (!comp.isVisible())
continue;
constraints = lookupConstraints(comp);
curX = constraints.gridx;
curY = constraints.gridy;
curWidth = constraints.gridwidth;
curHeight = constraints.gridheight;
/* If x or y is negative, then use relative positioning: */
if (curX < 0 && curY < 0) {
if(curRow >= 0)
curY = curRow;
else if(curCol >= 0)
curX = curCol;
else
curY = 0;
}
if (curX < 0) {
if (curHeight <= 0) {
curHeight += r.height - curY;
if (curHeight < 1)
curHeight = 1;
}
px = 0;
for (i = curY; i < (curY + curHeight); i++)
px = Math.max(px, xMaxArray[i]);
curX = px - curX - 1;
if(curX < 0)
curX = 0;
}
else if (curY < 0) {
if (curWidth <= 0) {
curWidth += r.width - curX;
if (curWidth < 1)
curWidth = 1;
}
py = 0;
for (i = curX; i < (curX + curWidth); i++){
py = Math.max(py, yMaxArray[i]);
}
curY = py - curY - 1;
if(curY < 0)
curY = 0;
}
if (curWidth <= 0) {
curWidth += r.width - curX;
if (curWidth < 1)
curWidth = 1;
}
if (curHeight <= 0) {
curHeight += r.height - curY;
if (curHeight < 1)
curHeight = 1;
}
px = curX + curWidth;
py = curY + curHeight;
for (i = curX; i < (curX + curWidth); i++) { yMaxArray[i] = py; }
for (i = curY; i < (curY + curHeight); i++) { xMaxArray[i] = px; }
/* Make negative sizes start a new row/column */
if (constraints.gridheight == 0 && constraints.gridwidth == 0)
curRow = curCol = -1;
if (constraints.gridheight == 0 && curRow < 0)
curCol = curX + curWidth;
else if (constraints.gridwidth == 0 && curCol < 0)
curRow = curY + curHeight;
/* Assign the new values to the gridbag slave */
constraints.tempX = curX;
constraints.tempY = curY;
constraints.tempWidth = curWidth;
constraints.tempHeight = curHeight;
anchor = constraints.anchor;
if (hasBaseline) {
switch(anchor) {
case GridBagConstraints.BASELINE:
case GridBagConstraints.BASELINE_LEADING:
case GridBagConstraints.BASELINE_TRAILING:
if (constraints.ascent >= 0) {
if (curHeight == 1) {
maxAscent[curY] =
Math.max(maxAscent[curY],
constraints.ascent);
maxDescent[curY] =
Math.max(maxDescent[curY],
constraints.descent);
}
else {
if (constraints.baselineResizeBehavior ==
Component.BaselineResizeBehavior.
CONSTANT_DESCENT) {
maxDescent[curY + curHeight - 1] =
Math.max(maxDescent[curY + curHeight
- 1],
constraints.descent);
}
else {
maxAscent[curY] = Math.max(maxAscent[curY],
constraints.ascent);
}
}
if (constraints.baselineResizeBehavior ==
Component.BaselineResizeBehavior.CONSTANT_DESCENT) {
baselineType[curY + curHeight - 1] |=
(1 << constraints.
baselineResizeBehavior.ordinal());
}
else {
baselineType[curY] |= (1 << constraints.
baselineResizeBehavior.ordinal());
}
}
break;
case GridBagConstraints.ABOVE_BASELINE:
case GridBagConstraints.ABOVE_BASELINE_LEADING:
case GridBagConstraints.ABOVE_BASELINE_TRAILING:
// Component positioned above the baseline.
// To make the bottom edge of the component aligned
// with the baseline the bottom inset is
// added to the descent, the rest to the ascent.
pixels_diff = constraints.minHeight +
constraints.insets.top +
constraints.ipady;
maxAscent[curY] = Math.max(maxAscent[curY],
pixels_diff);
maxDescent[curY] = Math.max(maxDescent[curY],
constraints.insets.bottom);
break;
case GridBagConstraints.BELOW_BASELINE:
case GridBagConstraints.BELOW_BASELINE_LEADING:
case GridBagConstraints.BELOW_BASELINE_TRAILING:
// Component positioned below the baseline.
// To make the top edge of the component aligned
// with the baseline the top inset is
// added to the ascent, the rest to the descent.
pixels_diff = constraints.minHeight +
constraints.insets.bottom + constraints.ipady;
maxDescent[curY] = Math.max(maxDescent[curY],
pixels_diff);
maxAscent[curY] = Math.max(maxAscent[curY],
constraints.insets.top);
break;
}
}
}
r.weightX = new double[maximumArrayYIndex];
r.weightY = new double[maximumArrayXIndex];
r.minWidth = new int[maximumArrayYIndex];
r.minHeight = new int[maximumArrayXIndex];
/*
* Apply minimum row/column dimensions and weights
*/
if (columnWidths != null)
System.arraycopy(columnWidths, 0, r.minWidth, 0, columnWidths.length);
if (rowHeights != null)
System.arraycopy(rowHeights, 0, r.minHeight, 0, rowHeights.length);
if (columnWeights != null)
System.arraycopy(columnWeights, 0, r.weightX, 0, Math.min(r.weightX.length, columnWeights.length));
if (rowWeights != null)
System.arraycopy(rowWeights, 0, r.weightY, 0, Math.min(r.weightY.length, rowWeights.length));
/*
* Pass #3
*
* Distribute the minimun widths and weights:
*/
nextSize = Integer.MAX_VALUE;
for (i = 1;
i != Integer.MAX_VALUE;
i = nextSize, nextSize = Integer.MAX_VALUE) {
for (compindex = 0 ; compindex < components.length ; compindex++) {
comp = components[compindex];
if (!comp.isVisible())
continue;
constraints = lookupConstraints(comp);
if (constraints.tempWidth == i) {
px = constraints.tempX + constraints.tempWidth; /* right column */
/*
* Figure out if we should use this slave\'s weight. If the weight
* is less than the total weight spanned by the width of the cell,
* then discard the weight. Otherwise split the difference
* according to the existing weights.
*/
weight_diff = constraints.weightx;
for (k = constraints.tempX; k < px; k++)
weight_diff -= r.weightX[k];
if (weight_diff > 0.0) {
weight = 0.0;
for (k = constraints.tempX; k < px; k++)
weight += r.weightX[k];
for (k = constraints.tempX; weight > 0.0 && k < px; k++) {
double wt = r.weightX[k];
double dx = (wt * weight_diff) / weight;
r.weightX[k] += dx;
weight_diff -= dx;
weight -= wt;
}
/* Assign the remainder to the rightmost cell */
r.weightX[px-1] += weight_diff;
}
/*
* Calculate the minWidth array values.
* First, figure out how wide the current slave needs to be.
* Then, see if it will fit within the current minWidth values.
* If it will not fit, add the difference according to the
* weightX array.
*/
pixels_diff =
constraints.minWidth + constraints.ipadx +
constraints.insets.left + constraints.insets.right;
for (k = constraints.tempX; k < px; k++)
pixels_diff -= r.minWidth[k];
if (pixels_diff > 0) {
weight = 0.0;
for (k = constraints.tempX; k < px; k++)
weight += r.weightX[k];
for (k = constraints.tempX; weight > 0.0 && k < px; k++) {
double wt = r.weightX[k];
int dx = (int)((wt * ((double)pixels_diff)) / weight);
r.minWidth[k] += dx;
pixels_diff -= dx;
weight -= wt;
}
/* Any leftovers go into the rightmost cell */
r.minWidth[px-1] += pixels_diff;
}
}
else if (constraints.tempWidth > i && constraints.tempWidth < nextSize)
nextSize = constraints.tempWidth;
if (constraints.tempHeight == i) {
py = constraints.tempY + constraints.tempHeight; /* bottom row */
/*
* Figure out if we should use this slave's weight. If the weight
* is less than the total weight spanned by the height of the cell,
* then discard the weight. Otherwise split it the difference
* according to the existing weights.
*/
weight_diff = constraints.weighty;
for (k = constraints.tempY; k < py; k++)
weight_diff -= r.weightY[k];
if (weight_diff > 0.0) {
weight = 0.0;
for (k = constraints.tempY; k < py; k++)
weight += r.weightY[k];
for (k = constraints.tempY; weight > 0.0 && k < py; k++) {
double wt = r.weightY[k];
double dy = (wt * weight_diff) / weight;
r.weightY[k] += dy;
weight_diff -= dy;
weight -= wt;
}
/* Assign the remainder to the bottom cell */
r.weightY[py-1] += weight_diff;
}
/*
* Calculate the minHeight array values.
* First, figure out how tall the current slave needs to be.
* Then, see if it will fit within the current minHeight values.
* If it will not fit, add the difference according to the
* weightY array.
*/
pixels_diff = -1;
if (hasBaseline) {
switch(constraints.anchor) {
case GridBagConstraints.BASELINE:
case GridBagConstraints.BASELINE_LEADING:
case GridBagConstraints.BASELINE_TRAILING:
if (constraints.ascent >= 0) {
if (constraints.tempHeight == 1) {
pixels_diff =
maxAscent[constraints.tempY] +
maxDescent[constraints.tempY];
}
else if (constraints.baselineResizeBehavior !=
Component.BaselineResizeBehavior.
CONSTANT_DESCENT) {
pixels_diff =
maxAscent[constraints.tempY] +
constraints.descent;
}
else {
pixels_diff = constraints.ascent +
maxDescent[constraints.tempY +
constraints.tempHeight - 1];
}
}
break;
case GridBagConstraints.ABOVE_BASELINE:
case GridBagConstraints.ABOVE_BASELINE_LEADING:
case GridBagConstraints.ABOVE_BASELINE_TRAILING:
pixels_diff = constraints.insets.top +
constraints.minHeight +
constraints.ipady +
maxDescent[constraints.tempY];
break;
case GridBagConstraints.BELOW_BASELINE:
case GridBagConstraints.BELOW_BASELINE_LEADING:
case GridBagConstraints.BELOW_BASELINE_TRAILING:
pixels_diff = maxAscent[constraints.tempY] +
constraints.minHeight +
constraints.insets.bottom +
constraints.ipady;
break;
}
}
if (pixels_diff == -1) {
pixels_diff =
constraints.minHeight + constraints.ipady +
constraints.insets.top +
constraints.insets.bottom;
}
for (k = constraints.tempY; k < py; k++)
pixels_diff -= r.minHeight[k];
if (pixels_diff > 0) {
weight = 0.0;
for (k = constraints.tempY; k < py; k++)
weight += r.weightY[k];
for (k = constraints.tempY; weight > 0.0 && k < py; k++) {
double wt = r.weightY[k];
int dy = (int)((wt * ((double)pixels_diff)) / weight);
r.minHeight[k] += dy;
pixels_diff -= dy;
weight -= wt;
}
/* Any leftovers go into the bottom cell */
r.minHeight[py-1] += pixels_diff;
}
}
else if (constraints.tempHeight > i &&
constraints.tempHeight < nextSize)
nextSize = constraints.tempHeight;
}
}
return r;
}
} //getLayoutInfo()
/**
* Calculate the baseline for the specified component.
* If {@code c} is positioned along it's baseline, the baseline is
* obtained and the {@code constraints} ascent, descent and
* baseline resize behavior are set from the component; and true is
* returned. Otherwise false is returned.
*/
private boolean calculateBaseline(Component c,
GridBagConstraints constraints,
Dimension size) {
int anchor = constraints.anchor;
if (anchor == GridBagConstraints.BASELINE ||
anchor == GridBagConstraints.BASELINE_LEADING ||
anchor == GridBagConstraints.BASELINE_TRAILING) {
// Apply the padding to the component, then ask for the baseline.
int w = size.width + constraints.ipadx;
int h = size.height + constraints.ipady;
constraints.ascent = c.getBaseline(w, h);
if (constraints.ascent >= 0) {
// Component has a baseline
int baseline = constraints.ascent;
// Adjust the ascent and descent to include the insets.
constraints.descent = h - constraints.ascent +
constraints.insets.bottom;
constraints.ascent += constraints.insets.top;
constraints.baselineResizeBehavior =
c.getBaselineResizeBehavior();
constraints.centerPadding = 0;
if (constraints.baselineResizeBehavior == Component.
BaselineResizeBehavior.CENTER_OFFSET) {
// Component has a baseline resize behavior of
// CENTER_OFFSET, calculate centerPadding and
// centerOffset (see the description of
// CENTER_OFFSET in the enum for detais on this
// algorithm).
int nextBaseline = c.getBaseline(w, h + 1);
constraints.centerOffset = baseline - h / 2;
if (h % 2 == 0) {
if (baseline != nextBaseline) {
constraints.centerPadding = 1;
}
}
else if (baseline == nextBaseline){
constraints.centerOffset--;
constraints.centerPadding = 1;
}
}
}
return true;
}
else {
constraints.ascent = -1;
return false;
}
}
/**
* Adjusts the x, y, width, and height fields to the correct
* values depending on the constraint geometry and pads.
* This method should only be used internally by
* <code>GridBagLayout</code>.
*
* @param constraints the constraints to be applied
* @param r the <code>Rectangle</code> to be adjusted
* @since 1.4
*/
protected void adjustForGravity(GridBagConstraints constraints,
Rectangle r) {
AdjustForGravity(constraints, r);
}
/**
* This method is obsolete and supplied for backwards
* compatibility only; new code should call {@link
* #adjustForGravity(java.awt.GridBagConstraints, java.awt.Rectangle)
* adjustForGravity} instead.
* This method is the same as <code>adjustForGravity</code>;
* refer to <code>adjustForGravity</code> for details
* on parameters.
*/
protected void AdjustForGravity(GridBagConstraints constraints,
Rectangle r) {
int diffx, diffy;
int cellY = r.y;
int cellHeight = r.height;
if (!rightToLeft) {
r.x += constraints.insets.left;
} else {
r.x -= r.width - constraints.insets.right;
}
r.width -= (constraints.insets.left + constraints.insets.right);
r.y += constraints.insets.top;
r.height -= (constraints.insets.top + constraints.insets.bottom);
diffx = 0;
if ((constraints.fill != GridBagConstraints.HORIZONTAL &&
constraints.fill != GridBagConstraints.BOTH)
&& (r.width > (constraints.minWidth + constraints.ipadx))) {
diffx = r.width - (constraints.minWidth + constraints.ipadx);
r.width = constraints.minWidth + constraints.ipadx;
}
diffy = 0;
if ((constraints.fill != GridBagConstraints.VERTICAL &&
constraints.fill != GridBagConstraints.BOTH)
&& (r.height > (constraints.minHeight + constraints.ipady))) {
diffy = r.height - (constraints.minHeight + constraints.ipady);
r.height = constraints.minHeight + constraints.ipady;
}
switch (constraints.anchor) {
case GridBagConstraints.BASELINE:
r.x += diffx/2;
alignOnBaseline(constraints, r, cellY, cellHeight);
break;
case GridBagConstraints.BASELINE_LEADING:
if (rightToLeft) {
r.x += diffx;
}
alignOnBaseline(constraints, r, cellY, cellHeight);
break;
case GridBagConstraints.BASELINE_TRAILING:
if (!rightToLeft) {
r.x += diffx;
}
alignOnBaseline(constraints, r, cellY, cellHeight);
break;
case GridBagConstraints.ABOVE_BASELINE:
r.x += diffx/2;
alignAboveBaseline(constraints, r, cellY, cellHeight);
break;
case GridBagConstraints.ABOVE_BASELINE_LEADING:
if (rightToLeft) {
r.x += diffx;
}
alignAboveBaseline(constraints, r, cellY, cellHeight);
break;
case GridBagConstraints.ABOVE_BASELINE_TRAILING:
if (!rightToLeft) {
r.x += diffx;
}
alignAboveBaseline(constraints, r, cellY, cellHeight);
break;
case GridBagConstraints.BELOW_BASELINE:
r.x += diffx/2;
alignBelowBaseline(constraints, r, cellY, cellHeight);
break;
case GridBagConstraints.BELOW_BASELINE_LEADING:
if (rightToLeft) {
r.x += diffx;
}
alignBelowBaseline(constraints, r, cellY, cellHeight);
break;
case GridBagConstraints.BELOW_BASELINE_TRAILING:
if (!rightToLeft) {
r.x += diffx;
}
alignBelowBaseline(constraints, r, cellY, cellHeight);
break;
case GridBagConstraints.CENTER:
r.x += diffx/2;
r.y += diffy/2;
break;
case GridBagConstraints.PAGE_START:
case GridBagConstraints.NORTH:
r.x += diffx/2;
break;
case GridBagConstraints.NORTHEAST:
r.x += diffx;
break;
case GridBagConstraints.EAST:
r.x += diffx;
r.y += diffy/2;
break;
case GridBagConstraints.SOUTHEAST:
r.x += diffx;
r.y += diffy;
break;
case GridBagConstraints.PAGE_END:
case GridBagConstraints.SOUTH:
r.x += diffx/2;
r.y += diffy;
break;
case GridBagConstraints.SOUTHWEST:
r.y += diffy;
break;
case GridBagConstraints.WEST:
r.y += diffy/2;
break;
case GridBagConstraints.NORTHWEST:
break;
case GridBagConstraints.LINE_START:
if (rightToLeft) {
r.x += diffx;
}
r.y += diffy/2;
break;
case GridBagConstraints.LINE_END:
if (!rightToLeft) {
r.x += diffx;
}
r.y += diffy/2;
break;
case GridBagConstraints.FIRST_LINE_START:
if (rightToLeft) {
r.x += diffx;
}
break;
case GridBagConstraints.FIRST_LINE_END:
if (!rightToLeft) {
r.x += diffx;
}
break;
case GridBagConstraints.LAST_LINE_START:
if (rightToLeft) {
r.x += diffx;
}
r.y += diffy;
break;
case GridBagConstraints.LAST_LINE_END:
if (!rightToLeft) {
r.x += diffx;
}
r.y += diffy;
break;
default:
throw new IllegalArgumentException("illegal anchor value");
}
}
/**
* Positions on the baseline.
*
* @param cellY the location of the row, does not include insets
* @param cellHeight the height of the row, does not take into account
* insets
* @param r available bounds for the component, is padded by insets and
* ipady
*/
private void alignOnBaseline(GridBagConstraints cons, Rectangle r,
int cellY, int cellHeight) {
if (cons.ascent >= 0) {
if (cons.baselineResizeBehavior == Component.
BaselineResizeBehavior.CONSTANT_DESCENT) {
// Anchor to the bottom.
// Baseline is at (cellY + cellHeight - maxDescent).
// Bottom of component (maxY) is at baseline + descent
// of component. We need to subtract the bottom inset here
// as the descent in the constraints object includes the
// bottom inset.
int maxY = cellY + cellHeight -
layoutInfo.maxDescent[cons.tempY + cons.tempHeight - 1] +
cons.descent - cons.insets.bottom;
if (!cons.isVerticallyResizable()) {
// Component not resizable, calculate y location
// from maxY - height.
r.y = maxY - cons.minHeight;
r.height = cons.minHeight;
} else {
// Component is resizable. As brb is constant descent,
// can expand component to fill region above baseline.
// Subtract out the top inset so that components insets
// are honored.
r.height = maxY - cellY - cons.insets.top;
}
}
else {
// BRB is not constant_descent
int baseline; // baseline for the row, relative to cellY
// Component baseline, includes insets.top
int ascent = cons.ascent;
if (layoutInfo.hasConstantDescent(cons.tempY)) {
// Mixed ascent/descent in same row, calculate position
// off maxDescent
baseline = cellHeight - layoutInfo.maxDescent[cons.tempY];
}
else {
// Only ascents/unknown in this row, anchor to top
baseline = layoutInfo.maxAscent[cons.tempY];
}
if (cons.baselineResizeBehavior == Component.
BaselineResizeBehavior.OTHER) {
// BRB is other, which means we can only determine
// the baseline by asking for it again giving the
// size we plan on using for the component.
boolean fits = false;
ascent = componentAdjusting.getBaseline(r.width, r.height);
if (ascent >= 0) {
// Component has a baseline, pad with top inset
// (this follows from calculateBaseline which
// does the same).
ascent += cons.insets.top;
}
if (ascent >= 0 && ascent <= baseline) {
// Components baseline fits within rows baseline.
// Make sure the descent fits within the space as well.
if (baseline + (r.height - ascent - cons.insets.top) <=
cellHeight - cons.insets.bottom) {
// It fits, we're good.
fits = true;
}
else if (cons.isVerticallyResizable()) {
// Doesn't fit, but it's resizable. Try
// again assuming we'll get ascent again.
int ascent2 = componentAdjusting.getBaseline(
r.width, cellHeight - cons.insets.bottom -
baseline + ascent);
if (ascent2 >= 0) {
ascent2 += cons.insets.top;
}
if (ascent2 >= 0 && ascent2 <= ascent) {
// It'll fit
r.height = cellHeight - cons.insets.bottom -
baseline + ascent;
ascent = ascent2;
fits = true;
}
}
}
if (!fits) {
// Doesn't fit, use min size and original ascent
ascent = cons.ascent;
r.width = cons.minWidth;
r.height = cons.minHeight;
}
}
// Reset the components y location based on
// components ascent and baseline for row. Because ascent
// includes the baseline
r.y = cellY + baseline - ascent + cons.insets.top;
if (cons.isVerticallyResizable()) {
switch(cons.baselineResizeBehavior) {
case CONSTANT_ASCENT:
r.height = Math.max(cons.minHeight,cellY + cellHeight -
r.y - cons.insets.bottom);
break;
case CENTER_OFFSET:
{
int upper = r.y - cellY - cons.insets.top;
int lower = cellY + cellHeight - r.y -
cons.minHeight - cons.insets.bottom;
int delta = Math.min(upper, lower);
delta += delta;
if (delta > 0 &&
(cons.minHeight + cons.centerPadding +
delta) / 2 + cons.centerOffset != baseline) {
// Off by 1
delta--;
}
r.height = cons.minHeight + delta;
r.y = cellY + baseline -
(r.height + cons.centerPadding) / 2 -
cons.centerOffset;
}
break;
case OTHER:
// Handled above
break;
default:
break;
}
}
}
}
else {
centerVertically(cons, r, cellHeight);
}
}
/**
* Positions the specified component above the baseline. That is
* the bottom edge of the component will be aligned along the baseline.
* If the row does not have a baseline, this centers the component.
*/
private void alignAboveBaseline(GridBagConstraints cons, Rectangle r,
int cellY, int cellHeight) {
if (layoutInfo.hasBaseline(cons.tempY)) {
int maxY; // Baseline for the row
if (layoutInfo.hasConstantDescent(cons.tempY)) {
// Prefer descent
maxY = cellY + cellHeight - layoutInfo.maxDescent[cons.tempY];
}
else {
// Prefer ascent
maxY = cellY + layoutInfo.maxAscent[cons.tempY];
}
if (cons.isVerticallyResizable()) {
// Component is resizable. Top edge is offset by top
// inset, bottom edge on baseline.
r.y = cellY + cons.insets.top;
r.height = maxY - r.y;
}
else {
// Not resizable.
r.height = cons.minHeight + cons.ipady;
r.y = maxY - r.height;
}
}
else {
centerVertically(cons, r, cellHeight);
}
}
/**
* Positions below the baseline.
*/
private void alignBelowBaseline(GridBagConstraints cons, Rectangle r,
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