org.eclipse.mylyn.tasks.ui/src/org/eclipse/mylyn/internal/tasks/ui/editors/FillWidthLayout.java - mylyn/org.eclipse.mylyn.tasks - Git at Google

 /*******************************************************************************
  * Copyright (c) 2004, 2008 David Green 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:
  *     David Green - initial API and implementation
  *******************************************************************************/

 package org.eclipse.mylyn.internal.tasks.ui.editors;

 import org.eclipse.core.runtime.Platform;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.custom.CTabFolder;
 import org.eclipse.swt.custom.ScrolledComposite;
 import org.eclipse.swt.graphics.Point;
 import org.eclipse.swt.graphics.Rectangle;
 import org.eclipse.swt.layout.FillLayout;
 import org.eclipse.swt.layout.GridLayout;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Control;
 import org.eclipse.swt.widgets.Layout;
 import org.eclipse.swt.widgets.ScrollBar;
 import org.eclipse.ui.forms.widgets.ILayoutExtension;
 import org.eclipse.ui.forms.widgets.Section;

 /**
  * A layout that uses the width hint or client area of a composite to recommend the width of its children, allowing
  * children to fill the width and specify their preferred height for a given width.
  *
  * Intended for use with a composite that contains a single child that should fill available horizontal space.
  *
  * @author David Green
  */
 class FillWidthLayout extends Layout implements ILayoutExtension {

 	private final int marginLeft;

 	private final int marginRight;

 	private final int marginTop;

 	private final int marginBottom;

 	private final int widthHintMargin;

 	private Composite layoutAdvisor;

 	private int lastWidthHint;

 	private Point lastComputedSize;

 	/**
 	 * create with 0 margins
 	 *
 	 */
 	public FillWidthLayout() {
 		this(0, 0, 0, 0);
 	}

 	/**
 	 * create while specifying margins
 	 *
 	 * @param marginLeft
 	 *            the left margin in pixels, or 0 if there should be none
 	 * @param marginRight
 	 *            the right margin in pixels, or 0 if there should be none
 	 * @param marginTop
 	 *            the top margin in pixels, or 0 if there should be none
 	 * @param marginBottom
 	 *            the bottom margin in pixels, or 0 if there should be none
 	 */
 	public FillWidthLayout(int marginLeft, int marginRight, int marginTop, int marginBottom) {
 		this(null, marginLeft, marginRight, marginTop, marginBottom);
 	}

 	/**
 	 * create specifying margins and a {@link #getLayoutAdvisor() layout advisor}.
 	 *
 	 * @param layoutAdvisor
 	 *            the composite that is used to advise on layout based on its {@link Composite#getClientArea() client
 	 *            area}.
 	 * @param marginLeft
 	 *            the left margin in pixels, or 0 if there should be none
 	 * @param marginRight
 	 *            the right margin in pixels, or 0 if there should be none
 	 * @param marginTop
 	 *            the top margin in pixels, or 0 if there should be none
 	 * @param marginBottom
 	 *            the bottom margin in pixels, or 0 if there should be none
 	 */
 	public FillWidthLayout(Composite layoutAdvisor, int marginLeft, int marginRight, int marginTop, int marginBottom) {
 		this.layoutAdvisor = layoutAdvisor;
 		this.marginLeft = marginLeft;
 		this.marginRight = marginRight;
 		this.marginTop = marginTop;
 		this.marginBottom = marginBottom;
 		if (Platform.OS_MACOSX.equals(Platform.getOS())) {
 			this.widthHintMargin = 15;
 		} else {
 			this.widthHintMargin = 18;
 		}
 	}

 	/**
 	 * calculate the client area of the given container, accomodating for insets and margins.
 	 */
 	private int calculateWidthHint(Composite container) {
 		return calculateWidthHint(container, layoutAdvisor == null);
 	}

 	/**
 	 * calculate the client area of the given container, accomodating for insets and margins.
 	 */
 	private int calculateWidthHint(Composite container, boolean layoutAdvisorHit) {
 		if (container == layoutAdvisor) {
 			layoutAdvisorHit = true;
 		}
 		Rectangle clientArea = container.getClientArea();
 		int horizontalMargin = 0;
 		if (clientArea.width <= 1 || !layoutAdvisorHit) { // sometimes client area is incorrectly reported as 1
 			clientArea.width = calculateWidthHint(container.getParent(), layoutAdvisorHit);
 		}
 		Layout bodyLayout = container.getLayout();
 		if (bodyLayout instanceof GridLayout) {
 			GridLayout gridLayout = (GridLayout) bodyLayout;
 			horizontalMargin = (gridLayout.marginWidth * 2) + gridLayout.marginLeft + gridLayout.marginRight;
 		} else if (bodyLayout instanceof FillLayout) {
 			FillLayout fillLayout = (FillLayout) bodyLayout;
 			horizontalMargin = fillLayout.marginWidth * 2;
 		} else if (container instanceof Section) {
 			horizontalMargin = ((Section) container).marginWidth * 2;
 		} else if (container instanceof CTabFolder) {
 			CTabFolder folder = (CTabFolder) container;
 			horizontalMargin = folder.marginWidth * 2;
 		}
 		if (container instanceof ScrolledComposite) {
 			ScrolledComposite composite = (ScrolledComposite) container;
 			ScrollBar verticalBar = composite.getVerticalBar();
 			if (verticalBar != null) {
 				int verticalBarWidth = verticalBar.getSize().x;
 				horizontalMargin += Math.max(15, verticalBarWidth);
 			}
 		}
 		return clientArea.width - horizontalMargin;
 	}

 	@Override
 	protected Point computeSize(Composite composite, int widthHint, int heightHint, boolean flushCache) {
 		Control[] children = composite.getChildren();
 		if (children.length == 0) {
 			return new Point(0, 0);
 		}
 		if (widthHint <= 0) {
 			widthHint = calculateWidthHint(composite);
 			widthHint -= widthHintMargin;
 		}

 		int horizontalMargin = marginLeft + marginRight;
 		if (widthHint < horizontalMargin) {
 			widthHint = horizontalMargin;
 		}

 		if (lastComputedSize == null || widthHint != lastWidthHint) {
 			int resultX = 1;
 			int resultY = 1;
 			for (Control control : children) {
 				Point sz = control.computeSize(widthHint - horizontalMargin, -1, flushCache);
 				resultX = Math.max(resultX, sz.x);
 				resultY = Math.max(resultY, sz.y);
 			}

 			lastWidthHint = widthHint;
 			lastComputedSize = new Point(resultX + horizontalMargin, resultY + marginTop + marginBottom);
 		}
 		return new Point(lastComputedSize.x, lastComputedSize.y + 1);
 	}

 	@Override
 	protected void layout(Composite composite, boolean flushCache) {
 		Rectangle area = composite.getClientArea();
 		if (area.width == 0) {
 			area.width = calculateWidthHint(composite);
 		}

 		// account for margins
 		area.x += marginLeft;
 		area.y += marginTop;
 		area.width -= (marginRight + marginLeft);
 		area.height -= (marginBottom + marginTop);

 		Control[] children = composite.getChildren();
 		for (Control control : children) {
 			control.setBounds(area);
 		}
 	}

 	/**
 	 * the composite that is used to advise on layout based on its {@link Composite#getClientArea() client area}.
 	 *
 	 * @return the layout advisor, or null if there is none
 	 */
 	public Composite getLayoutAdvisor() {
 		return layoutAdvisor;
 	}

 	/**
 	 * the composite that is used to advise on layout based on its {@link Composite#getClientArea() client area}.
 	 *
 	 * @param layoutAdvisor
 	 *            the layout advisor, or null if there is none
 	 */
 	public void setLayoutAdvisor(Composite layoutAdvisor) {
 		this.layoutAdvisor = layoutAdvisor;
 	}

 	/**
 	 * Flushes all cached information about control sizes.
 	 */
 	public void flush() {
 		lastComputedSize = null;
 	}

 	public int computeMaximumWidth(Composite parent, boolean changed) {
 		int width = marginLeft + marginRight;
 		Control[] children = parent.getChildren();
 		for (Control control : children) {
 			width = Math.max(control.computeSize(SWT.DEFAULT, 0, changed).x + marginLeft + marginRight, width);
 		}
 		return width;
 	}

 	public int computeMinimumWidth(Composite parent, boolean changed) {
 		int width = marginLeft + marginRight;
 //		Control[] children = parent.getChildren();
 //		for (Control control : children) {
 //			width = Math.max(control.computeSize(0, SWT.DEFAULT, changed).x + marginLeft + marginRight, width);
 //		}
 		return width;
 	}

 }
	/*******************************************************************************
	* Copyright (c) 2004, 2008 David Green 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:
	* David Green - initial API and implementation
	*******************************************************************************/

	package org.eclipse.mylyn.internal.tasks.ui.editors;

	import org.eclipse.core.runtime.Platform;
	import org.eclipse.swt.SWT;
	import org.eclipse.swt.custom.CTabFolder;
	import org.eclipse.swt.custom.ScrolledComposite;
	import org.eclipse.swt.graphics.Point;
	import org.eclipse.swt.graphics.Rectangle;
	import org.eclipse.swt.layout.FillLayout;
	import org.eclipse.swt.layout.GridLayout;
	import org.eclipse.swt.widgets.Composite;
	import org.eclipse.swt.widgets.Control;
	import org.eclipse.swt.widgets.Layout;
	import org.eclipse.swt.widgets.ScrollBar;
	import org.eclipse.ui.forms.widgets.ILayoutExtension;
	import org.eclipse.ui.forms.widgets.Section;

	/**
	* A layout that uses the width hint or client area of a composite to recommend the width of its children, allowing
	* children to fill the width and specify their preferred height for a given width.
	*
	* Intended for use with a composite that contains a single child that should fill available horizontal space.
	*
	* @author David Green
	*/
	class FillWidthLayout extends Layout implements ILayoutExtension {

	private final int marginLeft;

	private final int marginRight;

	private final int marginTop;

	private final int marginBottom;

	private final int widthHintMargin;

	private Composite layoutAdvisor;

	private int lastWidthHint;

	private Point lastComputedSize;

	/**
	* create with 0 margins
	*
	*/
	public FillWidthLayout() {
	this(0, 0, 0, 0);
	}

	/**
	* create while specifying margins
	*
	* @param marginLeft
	* the left margin in pixels, or 0 if there should be none
	* @param marginRight
	* the right margin in pixels, or 0 if there should be none
	* @param marginTop
	* the top margin in pixels, or 0 if there should be none
	* @param marginBottom
	* the bottom margin in pixels, or 0 if there should be none
	*/
	public FillWidthLayout(int marginLeft, int marginRight, int marginTop, int marginBottom) {
	this(null, marginLeft, marginRight, marginTop, marginBottom);
	}

	/**
	* create specifying margins and a {@link #getLayoutAdvisor() layout advisor}.
	*
	* @param layoutAdvisor
	* the composite that is used to advise on layout based on its {@link Composite#getClientArea() client
	* area}.
	* @param marginLeft
	* the left margin in pixels, or 0 if there should be none
	* @param marginRight
	* the right margin in pixels, or 0 if there should be none
	* @param marginTop
	* the top margin in pixels, or 0 if there should be none
	* @param marginBottom
	* the bottom margin in pixels, or 0 if there should be none
	*/
	public FillWidthLayout(Composite layoutAdvisor, int marginLeft, int marginRight, int marginTop, int marginBottom) {
	this.layoutAdvisor = layoutAdvisor;
	this.marginLeft = marginLeft;
	this.marginRight = marginRight;
	this.marginTop = marginTop;
	this.marginBottom = marginBottom;
	if (Platform.OS_MACOSX.equals(Platform.getOS())) {
	this.widthHintMargin = 15;
	} else {
	this.widthHintMargin = 18;
	}
	}

	/**
	* calculate the client area of the given container, accomodating for insets and margins.
	*/
	private int calculateWidthHint(Composite container) {
	return calculateWidthHint(container, layoutAdvisor == null);
	}

	/**
	* calculate the client area of the given container, accomodating for insets and margins.
	*/
	private int calculateWidthHint(Composite container, boolean layoutAdvisorHit) {
	if (container == layoutAdvisor) {
	layoutAdvisorHit = true;
	}
	Rectangle clientArea = container.getClientArea();
	int horizontalMargin = 0;
	if (clientArea.width <= 1 \|\| !layoutAdvisorHit) { // sometimes client area is incorrectly reported as 1
	clientArea.width = calculateWidthHint(container.getParent(), layoutAdvisorHit);
	}
	Layout bodyLayout = container.getLayout();
	if (bodyLayout instanceof GridLayout) {
	GridLayout gridLayout = (GridLayout) bodyLayout;
	horizontalMargin = (gridLayout.marginWidth * 2) + gridLayout.marginLeft + gridLayout.marginRight;
	} else if (bodyLayout instanceof FillLayout) {
	FillLayout fillLayout = (FillLayout) bodyLayout;
	horizontalMargin = fillLayout.marginWidth * 2;
	} else if (container instanceof Section) {
	horizontalMargin = ((Section) container).marginWidth * 2;
	} else if (container instanceof CTabFolder) {
	CTabFolder folder = (CTabFolder) container;
	horizontalMargin = folder.marginWidth * 2;
	}
	if (container instanceof ScrolledComposite) {
	ScrolledComposite composite = (ScrolledComposite) container;
	ScrollBar verticalBar = composite.getVerticalBar();
	if (verticalBar != null) {
	int verticalBarWidth = verticalBar.getSize().x;
	horizontalMargin += Math.max(15, verticalBarWidth);
	}
	}
	return clientArea.width - horizontalMargin;
	}

	@Override
	protected Point computeSize(Composite composite, int widthHint, int heightHint, boolean flushCache) {
	Control[] children = composite.getChildren();
	if (children.length == 0) {
	return new Point(0, 0);
	}
	if (widthHint <= 0) {
	widthHint = calculateWidthHint(composite);
	widthHint -= widthHintMargin;
	}

	int horizontalMargin = marginLeft + marginRight;
	if (widthHint < horizontalMargin) {
	widthHint = horizontalMargin;
	}

	if (lastComputedSize == null \|\| widthHint != lastWidthHint) {
	int resultX = 1;
	int resultY = 1;
	for (Control control : children) {
	Point sz = control.computeSize(widthHint - horizontalMargin, -1, flushCache);
	resultX = Math.max(resultX, sz.x);
	resultY = Math.max(resultY, sz.y);
	}

	lastWidthHint = widthHint;
	lastComputedSize = new Point(resultX + horizontalMargin, resultY + marginTop + marginBottom);
	}
	return new Point(lastComputedSize.x, lastComputedSize.y + 1);
	}

	@Override
	protected void layout(Composite composite, boolean flushCache) {
	Rectangle area = composite.getClientArea();
	if (area.width == 0) {
	area.width = calculateWidthHint(composite);
	}

	// account for margins
	area.x += marginLeft;
	area.y += marginTop;
	area.width -= (marginRight + marginLeft);
	area.height -= (marginBottom + marginTop);

	Control[] children = composite.getChildren();
	for (Control control : children) {
	control.setBounds(area);
	}
	}

	/**
	* the composite that is used to advise on layout based on its {@link Composite#getClientArea() client area}.
	*
	* @return the layout advisor, or null if there is none
	*/
	public Composite getLayoutAdvisor() {
	return layoutAdvisor;
	}

	/**
	* the composite that is used to advise on layout based on its {@link Composite#getClientArea() client area}.
	*
	* @param layoutAdvisor
	* the layout advisor, or null if there is none
	*/
	public void setLayoutAdvisor(Composite layoutAdvisor) {
	this.layoutAdvisor = layoutAdvisor;
	}

	/**
	* Flushes all cached information about control sizes.
	*/
	public void flush() {
	lastComputedSize = null;
	}

	public int computeMaximumWidth(Composite parent, boolean changed) {
	int width = marginLeft + marginRight;
	Control[] children = parent.getChildren();
	for (Control control : children) {
	width = Math.max(control.computeSize(SWT.DEFAULT, 0, changed).x + marginLeft + marginRight, width);
	}
	return width;
	}

	public int computeMinimumWidth(Composite parent, boolean changed) {
	int width = marginLeft + marginRight;
	// Control[] children = parent.getChildren();
	// for (Control control : children) {
	// width = Math.max(control.computeSize(0, SWT.DEFAULT, changed).x + marginLeft + marginRight, width);
	// }
	return width;
	}

	}