/*******************************************************************************
* Copyright (c) 2000, 2008, 2012 IBM Corporation, Gerhardt Informatics Kft. 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
* Gerhardt Informatics Kft. - GEFGWT port
*******************************************************************************/
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
* @see <a href="http://www.eclipse.org/swt/">Sample code and further
* information</a>
*
* @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;
}
}