Attachment 223156 Details for Bug 393514 – Pure SWT test case

Pure SWT test case

DNDRepaintBug.java (text/x-java), 5.94 KB, created by Peter Severin

on 2012-11-04 23:35:38 EST

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Filename:

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Creator: Peter Severin

Created: 2012-11-04 23:35:38 EST

Size: 5.94 KB

patch

obsolete

>package org.eclipse.swt.snippets;
>
>import org.eclipse.swt.SWT;
>import org.eclipse.swt.dnd.DND;
>import org.eclipse.swt.dnd.DragSource;
>import org.eclipse.swt.dnd.DragSourceEvent;
>import org.eclipse.swt.dnd.DragSourceListener;
>import org.eclipse.swt.dnd.DropTarget;
>import org.eclipse.swt.dnd.DropTargetAdapter;
>import org.eclipse.swt.dnd.DropTargetEvent;
>import org.eclipse.swt.dnd.TextTransfer;
>import org.eclipse.swt.dnd.Transfer;
>import org.eclipse.swt.events.PaintEvent;
>import org.eclipse.swt.events.PaintListener;
>import org.eclipse.swt.graphics.GC;
>import org.eclipse.swt.graphics.Point;
>import org.eclipse.swt.graphics.Rectangle;
>import org.eclipse.swt.layout.GridData;
>import org.eclipse.swt.layout.GridLayout;
>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.Label;
>import org.eclipse.swt.widgets.Shell;
>import org.eclipse.swt.widgets.Tree;
>import org.eclipse.swt.widgets.TreeItem;
>
>/**
> * A test case that demonstrates repaint issues on drag over. The test case
> * consist of a drag source on the left and 2 drag targets on the right. Drag
> * source creates a source image in drag source event. Drop targets paint a red
> * rectangle under the cursor when an item is dragged over. One drag target uses
> * redraw calls to invalidate and force repaint. The other additionally calls
> * {@link Control#update()} to force an immediate repaint. This results in a
> * repaint issue under the mouse.
> */
>public class DNDRepaintBug {
>	public static void main(String[] args) {
>		final Display display = new Display();
>		final Shell shell = new Shell(display);
>		shell.setLayout(new GridLayout(3, true));
>
>		new Label(shell, SWT.NONE).setText("Drag items from here");
>		new Label(shell, SWT.NONE).setText("Drag over works OK");
>		new Label(shell, SWT.NONE).setText("Drag over has repaint issues");
>
>		final Tree tree = new Tree(shell, SWT.BORDER | SWT.MULTI);
>		tree.setLayoutData(new GridData(GridData.FILL_BOTH));
>		for (int i = 0; i < 10; i++) {
>			TreeItem item = new TreeItem(tree, SWT.NONE);
>			item.setText("item " + i);
>		}
>
>		Transfer[] types = new Transfer[] { TextTransfer.getInstance() };
>		int operations = DND.DROP_MOVE | DND.DROP_COPY | DND.DROP_LINK;
>
>		final DragSource source = new DragSource(tree, operations);
>		source.setTransfer(types);
>		final TreeItem[] dragSourceItem = new TreeItem[1];
>		source.addDragListener(new DragSourceListener() {
>			public void dragStart(DragSourceEvent event) {
>				TreeItem[] selection = tree.getSelection();
>				if (selection.length > 0 && selection[0].getItemCount() == 0) {
>					event.doit = true;
>					dragSourceItem[0] = selection[0];
>				} else {
>					event.doit = false;
>				}
>			};
>
>			public void dragSetData(DragSourceEvent event) {
>				event.data = dragSourceItem[0].getText();
>			}
>
>			public void dragFinished(DragSourceEvent event) {
>				if (event.detail == DND.DROP_MOVE)
>					dragSourceItem[0].dispose();
>				dragSourceItem[0] = null;
>			}
>		});
>
>		// Create drop area that only calls Control#redraw
>		createDropArea(shell, types, operations, false);
>		// Create a second drop area that also calls Control#update
>		createDropArea(shell, types, operations, true);
>
>		shell.setSize(600, 400);
>		shell.open();
>		while (!shell.isDisposed()) {
>			if (!display.readAndDispatch())
>				display.sleep();
>		}
>		display.dispose();
>	}
>
>	private static void createDropArea(Composite parent, Transfer[] types,
>			int operations, boolean forceUpdate) {
>		final DropArea dropArea = new DropArea(parent, SWT.BORDER);
>		dropArea.setForceUpdate(forceUpdate);
>		dropArea.setLayoutData(new GridData(GridData.FILL_BOTH));
>		DropTarget target = new DropTarget(dropArea, operations);
>		target.setTransfer(types);
>		target.addDropListener(new DropTargetAdapter() {
>			@Override
>			public void dragOver(DropTargetEvent event) {
>				paintHotspot(event);
>			}
>
>			private void paintHotspot(DropTargetEvent event) {
>				Point pt = dropArea.toControl(new Point(event.x, event.y));
>				pt.x -= pt.x % 50;
>				pt.y -= pt.y % 50;
>				dropArea.setHotSpot(new Rectangle(pt.x, pt.y, 50, 50));
>			}
>
>			@Override
>			public void dragEnter(DropTargetEvent event) {
>				paintHotspot(event);
>			}
>
>			@Override
>			public void dragOperationChanged(DropTargetEvent event) {
>				paintHotspot(event);
>			}
>
>			@Override
>			public void dragLeave(DropTargetEvent event) {
>				eraseHotspot();
>			}
>
>			@Override
>			public void drop(DropTargetEvent event) {
>				eraseHotspot();
>			}
>
>			private void eraseHotspot() {
>				dropArea.setHotSpot(null);
>			}
>		});
>	}
>
>	private static class DropArea extends Canvas {
>		private Rectangle hotSpot;
>
>		private boolean forceUpdate;
>
>		public DropArea(Composite parent, int style) {
>			super(parent, style);
>			addPaintListener(new PaintListener() {
>				@Override
>				public void paintControl(PaintEvent e) {
>					paint(e);
>				}
>			});
>		}
>
>		public void setForceUpdate(boolean forceUpdate) {
>			this.forceUpdate = forceUpdate;
>		}
>
>		public void setHotSpot(Rectangle hotSpot) {
>			if (!eq(hotSpot, this.hotSpot)) {
>				Rectangle oldHotSpot = this.hotSpot;
>				this.hotSpot = hotSpot;
>				if (oldHotSpot != null)
>					redrawRect(oldHotSpot);
>				if (hotSpot != null)
>					redrawRect(hotSpot);
>
>				if (forceUpdate)
>					update();
>			}
>		}
>
>		private void redrawRect(Rectangle r) {
>			redraw(r.x, r.y, r.width, r.height, false);
>		}
>
>		private boolean eq(Rectangle a, Rectangle b) {
>			if (a == null)
>				return b == null;
>			else
>				return a.equals(b);
>		}
>
>		private void paint(PaintEvent e) {
>			GC gc = e.gc;
>			Rectangle area = getClientArea();
>			gc.setBackground(gc.getDevice().getSystemColor(SWT.COLOR_WHITE));
>			gc.fillRectangle(area);
>			if (hotSpot != null) {
>				gc.setBackground(gc.getDevice().getSystemColor(SWT.COLOR_RED));
>				gc.fillRectangle(hotSpot);
>			}
>		}
>	}
>}

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Attachments on bug 393514: 223155 | 223156 | 223157 | 223158