| /******************************************************************************* |
| * Copyright (c) 2000, 2006 IBM Corporation and others. All rights reserved. |
| * This program and the accompanying materials are made available under the |
| * terms of the Eclipse Public License v1.0 which accompanies this distribution, |
| * and is available at http://www.eclipse.org/legal/epl-v10.html Contributors: |
| * IBM Corporation - initial API and implementation |
| ******************************************************************************/ |
| package org.eclipse.swt.layout; |
| |
| import org.eclipse.swt.SWT; |
| import org.eclipse.swt.graphics.Point; |
| import org.eclipse.swt.widgets.Control; |
| |
| /** |
| * Instances of this class are used to define the attachments of a control in a |
| * <code>FormLayout</code>. |
| * <p> |
| * To set a <code>FormData</code> object into a control, you use the |
| * <code>setLayoutData ()</code> method. To define attachments for the |
| * <code>FormData</code>, set the fields directly, like this: |
| * |
| * <pre> |
| * FormData data = new FormData(); |
| * data.left = new FormAttachment( 0, 5 ); |
| * data.right = new FormAttachment( 100, -5 ); |
| * button.setLayoutData( formData ); |
| * </pre> |
| * |
| * </p> |
| * <p> |
| * <code>FormData</code> contains the <code>FormAttachments</code> for each |
| * edge of the control that the <code>FormLayout</code> uses to determine the |
| * size and position of the control. <code>FormData</code> objects also allow |
| * you to set the width and height of controls within a <code>FormLayout</code>. |
| * </p> |
| * |
| * @see FormLayout |
| * @see FormAttachment |
| * @since 2.0 |
| */ |
| public final class FormData { |
| |
| /** |
| * width specifies the preferred width in pixels. This value is the wHint |
| * passed into Control.computeSize(int, int, boolean) to determine the |
| * preferred size of the control. The default value is SWT.DEFAULT. |
| * |
| * @see Control#computeSize(int, int, boolean) |
| */ |
| public int width = SWT.DEFAULT; |
| /** |
| * height specifies the preferred height in pixels. This value is the hHint |
| * passed into Control.computeSize(int, int, boolean) to determine the |
| * preferred size of the control. The default value is SWT.DEFAULT. |
| * |
| * @see Control#computeSize(int, int, boolean) |
| */ |
| public int height = SWT.DEFAULT; |
| /** |
| * left specifies the attachment of the left side of the control. |
| */ |
| public FormAttachment left; |
| /** |
| * right specifies the attachment of the right side of the control. |
| */ |
| public FormAttachment right; |
| /** |
| * top specifies the attachment of the top of the control. |
| */ |
| public FormAttachment top; |
| /** |
| * bottom specifies the attachment of the bottom of the control. |
| */ |
| public FormAttachment bottom; |
| int cacheWidth = -1, cacheHeight = -1; |
| int defaultWhint, defaultHhint, defaultWidth = -1, defaultHeight = -1; |
| int currentWhint, currentHhint, currentWidth = -1, currentHeight = -1; |
| FormAttachment cacheLeft, cacheRight, cacheTop, cacheBottom; |
| boolean isVisited, needed; |
| |
| /** |
| * Constructs a new instance of FormData using default values. |
| */ |
| public FormData() { |
| } |
| |
| /** |
| * Constructs a new instance of FormData according to the parameters. A value |
| * of SWT.DEFAULT indicates that no minimum width or no minimum height is |
| * specified. |
| * |
| * @param width a minimum width for the control |
| * @param height a minimum height for the control |
| */ |
| public FormData( int width, int height ) { |
| this.width = width; |
| this.height = height; |
| } |
| |
| void computeSize( Control control, int wHint, int hHint, boolean flushCache ) |
| { |
| if( cacheWidth != -1 && cacheHeight != -1 ) |
| return; |
| if( wHint == this.width && hHint == this.height ) { |
| if( defaultWidth == -1 |
| || defaultHeight == -1 |
| || wHint != defaultWhint |
| || hHint != defaultHhint ) |
| { |
| Point size = control.computeSize( wHint, hHint, flushCache ); |
| defaultWhint = wHint; |
| defaultHhint = hHint; |
| defaultWidth = size.x; |
| defaultHeight = size.y; |
| } |
| cacheWidth = defaultWidth; |
| cacheHeight = defaultHeight; |
| return; |
| } |
| if( currentWidth == -1 |
| || currentHeight == -1 |
| || wHint != currentWhint |
| || hHint != currentHhint ) |
| { |
| Point size = control.computeSize( wHint, hHint, flushCache ); |
| currentWhint = wHint; |
| currentHhint = hHint; |
| currentWidth = size.x; |
| currentHeight = size.y; |
| } |
| cacheWidth = currentWidth; |
| cacheHeight = currentHeight; |
| } |
| |
| void flushCache() { |
| cacheWidth = cacheHeight = -1; |
| defaultHeight = defaultWidth = -1; |
| currentHeight = currentWidth = -1; |
| } |
| |
| int getWidth( Control control, boolean flushCache ) { |
| needed = true; |
| computeSize( control, width, height, flushCache ); |
| return cacheWidth; |
| } |
| |
| int getHeight( Control control, boolean flushCache ) { |
| computeSize( control, width, height, flushCache ); |
| return cacheHeight; |
| } |
| |
| FormAttachment getBottomAttachment( Control control, |
| int spacing, |
| boolean flushCache ) |
| { |
| if( cacheBottom != null ) |
| return cacheBottom; |
| if( isVisited ) |
| return cacheBottom = new FormAttachment( 0, getHeight( control, |
| flushCache ) ); |
| if( bottom == null ) { |
| if( top == null ) |
| return cacheBottom = new FormAttachment( 0, getHeight( control, |
| flushCache ) ); |
| return cacheBottom = getTopAttachment( control, spacing, flushCache ).plus( getHeight( control, |
| flushCache ) ); |
| } |
| Control bottomControl = bottom.control; |
| if( bottomControl != null ) { |
| if( bottomControl.isDisposed() ) { |
| bottom.control = bottomControl = null; |
| } else { |
| if( bottomControl.getParent() != control.getParent() ) { |
| bottomControl = null; |
| } |
| } |
| } |
| if( bottomControl == null ) |
| return cacheBottom = bottom; |
| isVisited = true; |
| FormData bottomData = ( FormData )bottomControl.getLayoutData(); |
| FormAttachment bottomAttachment = bottomData.getBottomAttachment( bottomControl, |
| spacing, |
| flushCache ); |
| switch( bottom.alignment ) { |
| case SWT.BOTTOM: |
| cacheBottom = bottomAttachment.plus( bottom.offset ); |
| break; |
| case SWT.CENTER: { |
| FormAttachment topAttachment = bottomData.getTopAttachment( bottomControl, |
| spacing, |
| flushCache ); |
| FormAttachment bottomHeight = bottomAttachment.minus( topAttachment ); |
| cacheBottom = bottomAttachment.minus( bottomHeight.minus( getHeight( control, |
| flushCache ) ) |
| .divide( 2 ) ); |
| break; |
| } |
| default: { |
| FormAttachment topAttachment = bottomData.getTopAttachment( bottomControl, |
| spacing, |
| flushCache ); |
| cacheBottom = topAttachment.plus( bottom.offset - spacing ); |
| break; |
| } |
| } |
| isVisited = false; |
| return cacheBottom; |
| } |
| |
| FormAttachment getLeftAttachment( Control control, |
| int spacing, |
| boolean flushCache ) |
| { |
| if( cacheLeft != null ) |
| return cacheLeft; |
| if( isVisited ) |
| return cacheLeft = new FormAttachment( 0, 0 ); |
| if( left == null ) { |
| if( right == null ) |
| return cacheLeft = new FormAttachment( 0, 0 ); |
| return cacheLeft = getRightAttachment( control, spacing, flushCache ).minus( getWidth( control, |
| flushCache ) ); |
| } |
| Control leftControl = left.control; |
| if( leftControl != null ) { |
| if( leftControl.isDisposed() ) { |
| left.control = leftControl = null; |
| } else { |
| if( leftControl.getParent() != control.getParent() ) { |
| leftControl = null; |
| } |
| } |
| } |
| if( leftControl == null ) |
| return cacheLeft = left; |
| isVisited = true; |
| FormData leftData = ( FormData )leftControl.getLayoutData(); |
| FormAttachment leftAttachment = leftData.getLeftAttachment( leftControl, |
| spacing, |
| flushCache ); |
| switch( left.alignment ) { |
| case SWT.LEFT: |
| cacheLeft = leftAttachment.plus( left.offset ); |
| break; |
| case SWT.CENTER: { |
| FormAttachment rightAttachment = leftData.getRightAttachment( leftControl, |
| spacing, |
| flushCache ); |
| FormAttachment leftWidth = rightAttachment.minus( leftAttachment ); |
| cacheLeft = leftAttachment.plus( leftWidth.minus( getWidth( control, |
| flushCache ) ) |
| .divide( 2 ) ); |
| break; |
| } |
| default: { |
| FormAttachment rightAttachment = leftData.getRightAttachment( leftControl, |
| spacing, |
| flushCache ); |
| cacheLeft = rightAttachment.plus( left.offset + spacing ); |
| } |
| } |
| isVisited = false; |
| return cacheLeft; |
| } |
| |
| String getName() { |
| String string = getClass().getName(); |
| int index = string.lastIndexOf( '.' ); |
| if( index == -1 ) |
| return string; |
| return string.substring( index + 1, string.length() ); |
| } |
| |
| FormAttachment getRightAttachment( Control control, |
| int spacing, |
| boolean flushCache ) |
| { |
| if( cacheRight != null ) |
| return cacheRight; |
| if( isVisited ) |
| return cacheRight = new FormAttachment( 0, getWidth( control, flushCache ) ); |
| if( right == null ) { |
| if( left == null ) |
| return cacheRight = new FormAttachment( 0, getWidth( control, |
| flushCache ) ); |
| return cacheRight = getLeftAttachment( control, spacing, flushCache ).plus( getWidth( control, |
| flushCache ) ); |
| } |
| Control rightControl = right.control; |
| if( rightControl != null ) { |
| if( rightControl.isDisposed() ) { |
| right.control = rightControl = null; |
| } else { |
| if( rightControl.getParent() != control.getParent() ) { |
| rightControl = null; |
| } |
| } |
| } |
| if( rightControl == null ) |
| return cacheRight = right; |
| isVisited = true; |
| FormData rightData = ( FormData )rightControl.getLayoutData(); |
| FormAttachment rightAttachment = rightData.getRightAttachment( rightControl, |
| spacing, |
| flushCache ); |
| switch( right.alignment ) { |
| case SWT.RIGHT: |
| cacheRight = rightAttachment.plus( right.offset ); |
| break; |
| case SWT.CENTER: { |
| FormAttachment leftAttachment = rightData.getLeftAttachment( rightControl, |
| spacing, |
| flushCache ); |
| FormAttachment rightWidth = rightAttachment.minus( leftAttachment ); |
| cacheRight = rightAttachment.minus( rightWidth.minus( getWidth( control, |
| flushCache ) ) |
| .divide( 2 ) ); |
| break; |
| } |
| default: { |
| FormAttachment leftAttachment = rightData.getLeftAttachment( rightControl, |
| spacing, |
| flushCache ); |
| cacheRight = leftAttachment.plus( right.offset - spacing ); |
| break; |
| } |
| } |
| isVisited = false; |
| return cacheRight; |
| } |
| |
| FormAttachment getTopAttachment( Control control, |
| int spacing, |
| boolean flushCache ) |
| { |
| if( cacheTop != null ) |
| return cacheTop; |
| if( isVisited ) |
| return cacheTop = new FormAttachment( 0, 0 ); |
| if( top == null ) { |
| if( bottom == null ) |
| return cacheTop = new FormAttachment( 0, 0 ); |
| return cacheTop = getBottomAttachment( control, spacing, flushCache ).minus( getHeight( control, |
| flushCache ) ); |
| } |
| Control topControl = top.control; |
| if( topControl != null ) { |
| if( topControl.isDisposed() ) { |
| top.control = topControl = null; |
| } else { |
| if( topControl.getParent() != control.getParent() ) { |
| topControl = null; |
| } |
| } |
| } |
| if( topControl == null ) |
| return cacheTop = top; |
| isVisited = true; |
| FormData topData = ( FormData )topControl.getLayoutData(); |
| FormAttachment topAttachment = topData.getTopAttachment( topControl, |
| spacing, |
| flushCache ); |
| switch( top.alignment ) { |
| case SWT.TOP: |
| cacheTop = topAttachment.plus( top.offset ); |
| break; |
| case SWT.CENTER: { |
| FormAttachment bottomAttachment = topData.getBottomAttachment( topControl, |
| spacing, |
| flushCache ); |
| FormAttachment topHeight = bottomAttachment.minus( topAttachment ); |
| cacheTop = topAttachment.plus( topHeight.minus( getHeight( control, |
| flushCache ) ) |
| .divide( 2 ) ); |
| break; |
| } |
| default: { |
| FormAttachment bottomAttachment = topData.getBottomAttachment( topControl, |
| spacing, |
| flushCache ); |
| cacheTop = bottomAttachment.plus( top.offset + spacing ); |
| break; |
| } |
| } |
| isVisited = false; |
| return cacheTop; |
| } |
| |
| /** |
| * Returns a string containing a concise, human-readable description of the |
| * receiver. |
| * |
| * @return a string representation of the FormData object |
| */ |
| public String toString() { |
| String string = getName() + " {"; |
| if( width != SWT.DEFAULT ) |
| string += "width=" + width + " "; |
| if( height != SWT.DEFAULT ) |
| string += "height=" + height + " "; |
| if( left != null ) |
| string += "left=" + left + " "; |
| if( right != null ) |
| string += "right=" + right + " "; |
| if( top != null ) |
| string += "top=" + top + " "; |
| if( bottom != null ) |
| string += "bottom=" + bottom + " "; |
| string = string.trim(); |
| string += "}"; |
| return string; |
| } |
| } |
