| /******************************************************************************* |
| * Copyright (c) 2004 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Common Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/cpl-v10.html |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.ui.examples.presentation.wrappedtabs; |
| |
| import org.eclipse.jface.util.Geometry; |
| import org.eclipse.swt.SWT; |
| import org.eclipse.swt.events.ControlEvent; |
| import org.eclipse.swt.events.ControlListener; |
| import org.eclipse.swt.events.DisposeEvent; |
| import org.eclipse.swt.events.DisposeListener; |
| import org.eclipse.swt.graphics.Point; |
| import org.eclipse.swt.graphics.Rectangle; |
| import org.eclipse.swt.widgets.Composite; |
| import org.eclipse.swt.widgets.Control; |
| import org.eclipse.swt.widgets.Event; |
| import org.eclipse.swt.widgets.Layout; |
| import org.eclipse.swt.widgets.Listener; |
| import org.eclipse.ui.internal.dnd.DragUtil; |
| import org.eclipse.ui.internal.dnd.SwtUtil; |
| |
| /** |
| * A ProxyControl is an invisible control whose size and position are linked |
| * with some target control. That is, when the dummy control is asked for its |
| * preferred size it returns the preferred size of the target. Changing the |
| * bounds of the dummy control also changes the bounds of the target. This allows |
| * any Composite to lay out a control that isn't one of its children. |
| * |
| * <p> |
| * For example, imagine you have a ViewForm and a ToolBar that share the same parent |
| * and you want the ToolBar to be located in the upper-right corner of the ViewForm. |
| * If the ToolBar were a child of the ViewForm, this could be done easily by calling |
| * viewForm.setTopRight(toolBar). However, this is impossible since ViewForm.setTopRight |
| * will only accept a child control. Instead, we create a ProxyControl as a child |
| * of the viewForm, and set the toolbar as its target. The ViewForm will treat |
| * the ProxyControl just like any other child, but it will actually be arranging the |
| * ToolBar. |
| * </p> |
| * <p>For example: |
| * </p> |
| * <code> |
| * // Create a ViewForm and a ToolBar that are siblings |
| * ViewForm viewForm = new ViewForm(parent, SWT.NONE); |
| * ToolBar toolBar = new ToolBar(parent, SWT.NONE); |
| * |
| * // Allow the ViewForm to control the position of the ToolBar by creating |
| * // a ProxyControl in the ViewForm that targets the ToolBar. |
| * ProxyControl toolBarProxy = new ProxyControl(viewForm); |
| * toolBarProxy.setTarget(toolBar); |
| * viewForm.setTopRight(toolBarProxy.getControl()); |
| * </code> |
| * |
| * <p> |
| * This is intended to simplify management of view toolbars in the presentation API. |
| * Presentation objects have no control over where the view toolbars are created in |
| * the widget hierarchy, but they may wish to control the position of the view toolbars |
| * using traditional SWT layouts and composites. |
| * </p> |
| */ |
| public class ProxyControl { |
| |
| /** |
| * Invisible dummy control |
| */ |
| private Composite control; |
| |
| /** |
| * Target control (possibly null) |
| */ |
| private Control target; |
| |
| /** |
| * Most specific common ancestor between the target and the proxy controls |
| */ |
| private Control commonAncestor; |
| |
| /** |
| * Visibility state of the proxy control the last time it had a non-null target. |
| * Note: when the target is set to null, we force the proxy to become invisible |
| * and use this variable to remember the initial state when we get a new non-null |
| * target. |
| */ |
| private boolean visible = true; |
| |
| /** |
| * Dispose listener. Breaks the link between the target and the proxy if either |
| * control is disposed. |
| */ |
| private DisposeListener disposeListener = new DisposeListener() { |
| public void widgetDisposed(DisposeEvent e) { |
| if (e.widget == target || e.widget == control) { |
| setTargetControl(null); |
| } |
| } |
| }; |
| |
| private Listener visibilityListener = new Listener() { |
| |
| public void handleEvent(Event event) { |
| if (target != null) { |
| visible = control.getVisible(); |
| target.setVisible(visible); |
| } |
| } |
| |
| }; |
| |
| /** |
| * Movement listener. Updates the bounds of the target to match the |
| * bounds of the dummy control. |
| */ |
| private ControlListener controlListener = new ControlListener() { |
| |
| public void controlMoved(ControlEvent e) { |
| ProxyControl.this.layout(); |
| } |
| |
| public void controlResized(ControlEvent e) { |
| //if (e.widget == control) { |
| // ProxyControl.this.layout(); |
| //} |
| } |
| |
| }; |
| |
| /** |
| * Creates a new ProxyControl as a child of the given parent. This is an invisible dummy |
| * control. If given a target, the ProxyControl will update the bounds of the target to |
| * match the bounds of the dummy control. |
| * |
| * @param parent parent composite |
| */ |
| public ProxyControl(Composite parent) { |
| // Create the invisible dummy composite |
| control = new Composite(parent, SWT.NO_BACKGROUND); |
| control.setVisible(false); |
| |
| // Attach a layout to the dummy composite. This is used to make the preferred |
| // size of the dummy match the preferred size of the target. |
| control.setLayout(new Layout() { |
| protected void layout (Composite composite, boolean flushCache) { |
| ProxyControl.this.layout(); |
| // does nothing. The bounds of the target are updated by the controlListener |
| } |
| |
| protected Point computeSize (Composite composite, int wHint, int hHint, boolean flushCache) { |
| if (target == null) { |
| // Note: If we returned (0,0), SWT would ignore the result and use a default value. |
| return new Point(1,1); |
| } |
| |
| return target.computeSize(wHint, hHint); |
| } |
| }); |
| |
| // Attach listeners to the dummy |
| control.addDisposeListener(disposeListener); |
| control.addListener(SWT.Show, visibilityListener); |
| control.addListener(SWT.Hide, visibilityListener); |
| } |
| |
| /** |
| * Sets the control whose position will be managed by this proxy |
| * |
| * @param target the control, or null if none |
| */ |
| public void setTargetControl(Control target) { |
| if (this.target != target) { |
| |
| if (this.target != null) { |
| for (Control next = control; next != commonAncestor && next != null; next = next.getParent()) { |
| next.removeControlListener(controlListener); |
| } |
| commonAncestor = null; |
| |
| // If we already had a target, detach the dispose listener |
| // (prevents memory leaks due to listeners) |
| if (!this.target.isDisposed()) { |
| this.target.removeDisposeListener(disposeListener); |
| } |
| } |
| |
| if (this.target == null && target != null) { |
| // If we had previously forced the dummy control invisible, restore its visibility |
| control.setVisible(visible); |
| } |
| |
| this.target = target; |
| |
| if (target != null) { |
| commonAncestor = SwtUtil.findCommonAncestor(this.target, control); |
| for (Control next = control; next != null && next != commonAncestor; next = next.getParent()) { |
| next.addControlListener(controlListener); |
| } |
| |
| // Make the new target's visiblity match the visibility of the dummy control |
| target.setVisible(control.getVisible()); |
| // Add a dispose listener. Ensures that the target is cleared |
| // if it is ever disposed. |
| target.addDisposeListener(disposeListener); |
| } else { |
| control.setVisible(false); |
| } |
| } |
| } |
| |
| /** |
| * Returns the target control (the control whose size is being managed) |
| * |
| * @return the target control (or null) |
| */ |
| public Control getTargetControl() { |
| if (target == null) { |
| return null; |
| } |
| |
| return target; |
| } |
| |
| /** |
| * Returns the proxy control |
| * |
| * @return the proxy control (not null) |
| */ |
| public Control getControl() { |
| return control; |
| } |
| |
| public Control getTarget() { |
| return target; |
| } |
| |
| /** |
| * Moves the target control on top of the dummy control. |
| */ |
| public void layout() { |
| if (getTargetControl() == null) { |
| return; |
| } |
| |
| // Compute the unclipped bounds of the target in display coordinates |
| Rectangle displayBounds = Geometry.toDisplay(control.getParent(), control.getBounds()); |
| |
| // Clip the bounds of the target so that it doesn't go outside the dummy control's parent |
| Rectangle clippingRegion = DragUtil.getDisplayBounds(control.getParent()); |
| displayBounds = displayBounds.intersection(clippingRegion); |
| |
| // Compute the bounds of the target, in the local coordinate system of its parent |
| Rectangle targetBounds = Geometry.toControl(getTargetControl().getParent(), displayBounds); |
| |
| // Move the target |
| getTargetControl().setBounds(targetBounds); |
| } |
| } |