Java tutorial
/******************************************************************************* * Copyright (c) 2004, 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 de.femodeling.e4.ui.progress.internal; import java.util.ArrayList; import java.util.List; import org.eclipse.core.runtime.Assert; import org.eclipse.jface.resource.JFaceResources; import org.eclipse.jface.viewers.IBaseLabelProvider; import org.eclipse.jface.viewers.ILabelProvider; import org.eclipse.swt.SWT; import org.eclipse.swt.events.DisposeEvent; import org.eclipse.swt.events.DisposeListener; import org.eclipse.swt.events.PaintEvent; import org.eclipse.swt.events.PaintListener; import org.eclipse.swt.graphics.FontMetrics; import org.eclipse.swt.graphics.GC; import org.eclipse.swt.graphics.Point; import org.eclipse.swt.graphics.Rectangle; import org.eclipse.swt.graphics.Transform; import org.eclipse.swt.widgets.Canvas; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.Control; import org.eclipse.swt.widgets.Display; import org.eclipse.swt.widgets.Widget; import de.femodeling.e4.ui.progress.IProgressConstants; /** * The ProgressCanvasViewer is the viewer used by progress windows. It displays text * on the canvas. */ public class ProgressCanvasViewer extends AbstractProgressViewer { Canvas canvas; Object[] displayedItems = new Object[0]; private final static List EMPTY_LIST = new ArrayList(); /** * Font metrics to use for determining pixel sizes. */ private FontMetrics fontMetrics; private int numShowItems = 1; private int maxCharacterWidth; private int orientation = SWT.HORIZONTAL; /** * Create a new instance of the receiver with the supplied * parent and style bits. * @param parent The composite the Canvas is created in * @param style style bits for the canvas * @param itemsToShow the number of items this will show * @param numChars The number of characters for the width hint. * @param side the side to display text, this helps determine horizontal vs vertical */ ProgressCanvasViewer(Composite parent, int style, int itemsToShow, int numChars, int orientation) { super(); this.orientation = orientation; numShowItems = itemsToShow; maxCharacterWidth = numChars; canvas = new Canvas(parent, style); hookControl(canvas); // Compute and store a font metric GC gc = new GC(canvas); gc.setFont(JFaceResources.getDefaultFont()); fontMetrics = gc.getFontMetrics(); gc.dispose(); initializeListeners(); } /** * NE: Copied from ContentViewer. We don't want the OpenStrategy hooked * in StructuredViewer.hookControl otherwise the canvas will take focus * since it has a key listener. We don't want this included in the window's * tab traversal order. Defeating it here is more self-contained then * setting the tab list on the shell or other parent composite. */ protected void hookControl(Control control) { control.addDisposeListener(new DisposeListener() { public void widgetDisposed(DisposeEvent event) { handleDispose(event); } }); } /* * (non-Javadoc) * * @see org.eclipse.jface.viewers.StructuredViewer#doFindInputItem(java.lang.Object) */ protected Widget doFindInputItem(Object element) { return null; // No widgets associated with items } /* * (non-Javadoc) * * @see org.eclipse.jface.viewers.StructuredViewer#doFindItem(java.lang.Object) */ protected Widget doFindItem(Object element) { return null; // No widgets associated with items } /* * (non-Javadoc) * * @see org.eclipse.jface.viewers.StructuredViewer#doUpdateItem(org.eclipse.swt.widgets.Widget, * java.lang.Object, boolean) */ protected void doUpdateItem(Widget item, Object element, boolean fullMap) { canvas.redraw(); } /* * (non-Javadoc) * * @see org.eclipse.jface.viewers.StructuredViewer#getSelectionFromWidget() */ protected List getSelectionFromWidget() { //No selection on a Canvas return EMPTY_LIST; } /* * (non-Javadoc) * * @see org.eclipse.jface.viewers.StructuredViewer#internalRefresh(java.lang.Object) */ protected void internalRefresh(Object element) { displayedItems = getSortedChildren(getRoot()); canvas.redraw(); } /* * (non-Javadoc) * * @see org.eclipse.jface.viewers.StructuredViewer#reveal(java.lang.Object) */ public void reveal(Object element) { //Nothing to do here as we do not scroll } /* * (non-Javadoc) * * @see org.eclipse.jface.viewers.StructuredViewer#setSelectionToWidget(java.util.List, * boolean) */ protected void setSelectionToWidget(List l, boolean reveal) { //Do nothing as there is no selection } /* * (non-Javadoc) * * @see org.eclipse.jface.viewers.Viewer#getControl() */ public Control getControl() { return canvas; } private void initializeListeners() { canvas.addPaintListener(new PaintListener() { /* * (non-Javadoc) * * @see org.eclipse.swt.events.PaintListener#paintControl(org.eclipse.swt.events.PaintEvent) */ public void paintControl(PaintEvent event) { GC gc = event.gc; Transform transform = null; if (orientation == SWT.VERTICAL) { transform = new Transform(event.display); transform.translate(IProgressConstants.TRIM_DEFAULT_HEIGHT, 0); transform.rotate(90); } ILabelProvider labelProvider = (ILabelProvider) getLabelProvider(); int itemCount = Math.min(displayedItems.length, numShowItems); int yOffset = 0; int xOffset = 0; if (numShowItems == 1) {//If there is a single item try to center it Rectangle clientArea = canvas.getParent().getClientArea(); if (orientation == SWT.HORIZONTAL) { int size = clientArea.height; yOffset = size - (fontMetrics.getHeight()); yOffset = yOffset / 2; } else { int size = clientArea.width; xOffset = size - (fontMetrics.getHeight()); xOffset = xOffset / 2; } } for (int i = 0; i < itemCount; i++) { String string = labelProvider.getText(displayedItems[i]); if (string == null) { string = "";//$NON-NLS-1$ } if (orientation == SWT.HORIZONTAL) { gc.drawString(string, 2, yOffset + (i * fontMetrics.getHeight()), true); } else { gc.setTransform(transform); gc.drawString(string, xOffset + (i * fontMetrics.getHeight()), 2, true); } } if (transform != null) transform.dispose(); } }); } /* (non-Javadoc) * @see org.eclipse.jface.viewers.ContentViewer#setLabelProvider(org.eclipse.jface.viewers.IBaseLabelProvider) */ public void setLabelProvider(IBaseLabelProvider labelProvider) { Assert.isTrue(labelProvider instanceof ILabelProvider); super.setLabelProvider(labelProvider); } /** * Get the size hints for the receiver. These are used for * layout data. * @return Point - the preferred x and y coordinates */ public Point getSizeHints() { Display display = canvas.getDisplay(); GC gc = new GC(canvas); FontMetrics fm = gc.getFontMetrics(); int charWidth = fm.getAverageCharWidth(); int charHeight = fm.getHeight(); int maxWidth = display.getBounds().width / 2; int maxHeight = display.getBounds().height / 6; int fontWidth = charWidth * maxCharacterWidth; int fontHeight = charHeight * numShowItems; if (maxWidth < fontWidth) { fontWidth = maxWidth; } if (maxHeight < fontHeight) { fontHeight = maxHeight; } gc.dispose(); return new Point(fontWidth, fontHeight); } /* (non-Javadoc) * @see org.eclipse.ui.internal.progress.AbstractProgressViewer#add(java.lang.Object[]) */ public void add(Object[] elements) { refresh(true); } /* (non-Javadoc) * @see org.eclipse.ui.internal.progress.AbstractProgressViewer#remove(java.lang.Object[]) */ public void remove(Object[] elements) { refresh(true); } }