Work around SWT 4.13 - 4.18 Win32 DnD bug 567422

[simantics/platform.git] / bundles / org.eclipse.swt.win32.win32.x86_64 / src / org / eclipse / swt / custom / ScrolledCompositeLayout.java

diff --git a/bundles/org.eclipse.swt.win32.win32.x86_64/src/org/eclipse/swt/custom/ScrolledCompositeLayout.java b/bundles/org.eclipse.swt.win32.win32.x86_64/src/org/eclipse/swt/custom/ScrolledCompositeLayout.java
new file mode 100644 (file)
index 0000000..435e7a5
--- /dev/null
+++ b/bundles/org.eclipse.swt.win32.win32.x86_64/src/org/eclipse/swt/custom/ScrolledCompositeLayout.java
@@ -0,0 +1,124 @@
+/*******************************************************************************
+ * Copyright (c) 2000, 2012 IBM Corporation and others.
+ *
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     IBM Corporation - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.swt.custom;
+
+import org.eclipse.swt.*;
+import org.eclipse.swt.graphics.*;
+import org.eclipse.swt.widgets.*;
+
+/**
+ * This class provides the layout for ScrolledComposite
+ *
+ * @see ScrolledComposite
+ */
+class ScrolledCompositeLayout extends Layout {
+
+       boolean inLayout = false;
+       static final int DEFAULT_WIDTH  = 64;
+       static final int DEFAULT_HEIGHT = 64;
+
+@Override
+protected Point computeSize(Composite composite, int wHint, int hHint, boolean flushCache) {
+       ScrolledComposite sc = (ScrolledComposite)composite;
+       Point size = new Point(DEFAULT_WIDTH, DEFAULT_HEIGHT);
+       if (sc.content != null) {
+               Point preferredSize = sc.content.computeSize(wHint, hHint, flushCache);
+               Point currentSize = sc.content.getSize();
+               size.x = sc.getExpandHorizontal() ? preferredSize.x : currentSize.x;
+               size.y = sc.getExpandVertical() ? preferredSize.y : currentSize.y;
+       }
+       size.x = Math.max(size.x, sc.minWidth);
+       size.y = Math.max(size.y, sc.minHeight);
+       if (wHint != SWT.DEFAULT) size.x = wHint;
+       if (hHint != SWT.DEFAULT) size.y = hHint;
+       return size;
+}
+
+@Override
+protected boolean flushCache(Control control) {
+       return true;
+}
+
+@Override
+protected void layout(Composite composite, boolean flushCache) {
+       if (inLayout) return;
+       ScrolledComposite sc = (ScrolledComposite)composite;
+       if (sc.content == null) return;
+       ScrollBar hBar = sc.getHorizontalBar();
+       ScrollBar vBar = sc.getVerticalBar();
+       if (hBar != null) {
+               if (hBar.getSize().y >= sc.getSize().y) {
+                       return;
+               }
+       }
+       if (vBar != null) {
+               if (vBar.getSize().x >= sc.getSize().x) {
+                       return;
+               }
+       }
+       inLayout = true;
+       Rectangle contentRect = sc.content.getBounds();
+       if (!sc.alwaysShowScroll) {
+               boolean hVisible = sc.needHScroll(contentRect, false);
+               boolean vVisible = sc.needVScroll(contentRect, hVisible);
+               if (!hVisible && vVisible) hVisible = sc.needHScroll(contentRect, vVisible);
+               if (hBar != null) hBar.setVisible(hVisible);
+               if (vBar != null) vBar.setVisible(vVisible);
+       }
+       Rectangle hostRect = sc.getClientArea();
+       if (sc.expandHorizontal) {
+               contentRect.width = Math.max(sc.minWidth, hostRect.width);
+       }
+       if (sc.expandVertical) {
+               contentRect.height = Math.max(sc.minHeight, hostRect.height);
+       }
+
+       GC gc = new GC (sc);
+       if (hBar != null) {
+               hBar.setMaximum (contentRect.width);
+               hBar.setThumb (Math.min (contentRect.width, hostRect.width));
+               hBar.setIncrement ((int) gc.getFontMetrics ().getAverageCharacterWidth ());
+               hBar.setPageIncrement (hostRect.width);
+               int hPage = contentRect.width - hostRect.width;
+               int hSelection = hBar.getSelection ();
+               if (hSelection >= hPage) {
+                       if (hPage <= 0) {
+                               hSelection = 0;
+                               hBar.setSelection(0);
+                       }
+                       contentRect.x = -hSelection;
+               }
+       }
+
+       if (vBar != null) {
+               vBar.setMaximum (contentRect.height);
+               vBar.setThumb (Math.min (contentRect.height, hostRect.height));
+               vBar.setIncrement (gc.getFontMetrics ().getHeight ());
+               vBar.setPageIncrement (hostRect.height);
+               int vPage = contentRect.height - hostRect.height;
+               int vSelection = vBar.getSelection ();
+               if (vSelection >= vPage) {
+                       if (vPage <= 0) {
+                               vSelection = 0;
+                               vBar.setSelection(0);
+                       }
+                       contentRect.y = -vSelection;
+               }
+       }
+       gc.dispose ();
+
+       sc.content.setBounds (contentRect);
+       inLayout = false;
+}
+}