Migrated source code from Simantics SVN

[simantics/platform.git] / bundles / org.simantics.utils.ui / src / org / simantics / utils / ui / awt / SwtInputBlocker.java

diff --git a/bundles/org.simantics.utils.ui/src/org/simantics/utils/ui/awt/SwtInputBlocker.java b/bundles/org.simantics.utils.ui/src/org/simantics/utils/ui/awt/SwtInputBlocker.java
new file mode 100644 (file)
index 0000000..cac9d56
--- /dev/null
+++ b/bundles/org.simantics.utils.ui/src/org/simantics/utils/ui/awt/SwtInputBlocker.java
@@ -0,0 +1,111 @@
+/*******************************************************************************\r
+ * Copyright (c) 2007 SAS Institute.\r
+ * All rights reserved. This program and the accompanying materials\r
+ * are made available under the terms of the Eclipse Public License v1.0\r
+ * which accompanies this distribution, and is available at\r
+ * http://www.eclipse.org/legal/epl-v10.html\r
+ *\r
+ * Contributors:\r
+ *     SAS Institute - initial API and implementation\r
+ *******************************************************************************/\r
+package org.simantics.utils.ui.awt;\r
+\r
+import org.eclipse.swt.SWT;\r
+import org.eclipse.swt.events.FocusAdapter;\r
+import org.eclipse.swt.events.FocusEvent;\r
+import org.eclipse.swt.widgets.Dialog;\r
+import org.eclipse.swt.widgets.Display;\r
+import org.eclipse.swt.widgets.Shell;\r
+\r
+\r
+\r
+class SwtInputBlocker extends Dialog {\r
+    static private SwtInputBlocker instance = null;\r
+    static private int blockCount = 0;\r
+    private Shell shell;\r
+\r
+    private SwtInputBlocker(Shell parent) {\r
+        super(parent, SWT.NONE); \r
+    }\r
+    \r
+    private Object open() {\r
+        assert Display.getCurrent() != null;     // On SWT event thread\r
+        \r
+        final Shell parent = getParent();\r
+        shell = new Shell(parent, SWT.APPLICATION_MODAL);\r
+        shell.setSize(0, 0);\r
+        shell.addFocusListener(new FocusAdapter() {\r
+            public void focusGained(FocusEvent e) {\r
+                // On some platforms (e.g. Linux/GTK), the 0x0 shell still appears as a dot \r
+                // on the screen, so make it invisible by moving it below other windows. This\r
+                // is unnecessary under Windows and causes a flash, so only make the call when necessary. \r
+                if (Platform.isGtk()) {\r
+                    shell.moveBelow(null);\r
+                }\r
+                AwtEnvironment.getInstance(shell.getDisplay()).requestAwtDialogFocus();\r
+            }\r
+        });\r
+        shell.open();\r
+        \r
+        Display display = parent.getDisplay();\r
+        while (!shell.isDisposed()) {\r
+            if (!display.readAndDispatch()) {\r
+                display.sleep();\r
+            }\r
+        }\r
+        return null;\r
+    }\r
+\r
+    private void close() {\r
+        assert shell != null;\r
+        \r
+        shell.dispose();\r
+    }\r
+\r
+    static void unblock() {\r
+        assert blockCount >= 0;\r
+        assert Display.getCurrent() != null;  // On SWT event thread\r
+\r
+        \r
+        // System.out.println("Deleting SWT blocker");\r
+        if (blockCount == 0) {\r
+            return;\r
+        }\r
+        if ((blockCount == 1) && (instance != null)) {\r
+            instance.close();\r
+            instance = null;\r
+        }\r
+        blockCount--;\r
+    }\r
+    \r
+    static void block() {\r
+        assert blockCount >= 0;\r
+        \r
+        // System.out.println("Creating SWT blocker");\r
+        final Display display = Display.getCurrent();\r
+        assert display != null;  // On SWT event thread\r
+        \r
+        blockCount++;\r
+        if (blockCount == 1) {\r
+            assert instance == null;  // should be no existing blocker\r
+            \r
+            // get a shell to parent the blocking dialog\r
+            Shell shell = AwtEnvironment.getInstance(display).getShell();\r
+\r
+            // If there is a shell to block, block input now. If there are no shells, \r
+            // then there is no input to block. In the case of no shells, we are not\r
+            // protecting against a shell that might get created later. This is a rare\r
+            // enough case to skip, at least for now. In the future, a listener could be \r
+            // added to cover it. \r
+            // TODO: if (shell==null) add listener to block shells created later?\r
+            //\r
+            // Block is implemented with a hidden modal dialog. Using setEnabled(false) is another option, but \r
+            // on some platforms that will grey the disabled controls.\r
+            if (shell != null) {\r
+                instance = new SwtInputBlocker(shell);\r
+                instance.open();\r
+            }\r
+        }\r
+    }\r
+\r
+}\r