class to hijack mouse events from a component for a while.

git-svn-id: https://samskivert.googlecode.com/svn/trunk@788 6335cc39-0255-0410-8fd6-9bcaacd3b74c
2002-06-27 00:14:52 +00:00
parent 4116a39b7b
commit bcab718966
1 changed files with 117 additions and 0 deletions
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+//
+// $Id: MouseHijacker.java,v 1.1 2002/06/27 00:14:52 ray Exp $
+
+package com.samskivert.swing.util;
+
+import java.awt.Component;
+
+import java.awt.event.MouseEvent;
+import java.awt.event.MouseListener;
+import java.awt.event.MouseMotionAdapter;
+import java.awt.event.MouseMotionListener;
+
+/**
+ * Hijacks normal mouse input from reaching the specified component's
+ * normal listeners. There is one special consideration it makes for your
+ * component: it tracks mouse movement events and will relay the last
+ * one to each MouseMotionListener before reinstating it on the component.
+ *
+ * Typically this will be used in conjunction with
+ * installation of your own listeners, like so:
+ *
+ * <pre>
+ *     public void startStuff (Component comp)
+ *     {
+ *         _hijacker = new MouseHijacker(comp);
+ *         comp.addMouseListener(this);
+ *     }
+ *
+ *     public void mouseClicked (MouseEvent evt)
+ *     {
+ *         doStuff();
+ *         endStuff();
+ *     }
+ *
+ *     protected void endStuff ()
+ *     {
+ *         Component comp = _hijacker.release();
+ *         comp.removeMouseListener(this);
+ *     }
+ *
+ *     protected MouseHijacker _hijacker;
+ * </pre>
+ */
+public class MouseHijacker
+{
+    /**
+     * Construct a mouse hijacker and hijack the specified component.
+     */
+    public MouseHijacker (Component comp)
+    {
+        _comp = comp;
+        hijack();
+    }
+
+    /**
+     * Hijack the component's mouse listeners.
+     */
+    public void hijack ()
+    {
+        _mls = _comp.getMouseListeners();
+        for (int ii=0; ii < _mls.length; ii++) {
+            _comp.removeMouseListener(_mls[ii]);
+        }
+
+        _mmls = _comp.getMouseMotionListeners();
+        for (int ii=0; ii < _mmls.length; ii++) {
+            _comp.removeMouseMotionListener(_mmls[ii]);
+        }
+
+        _comp.addMouseMotionListener(_motionCatcher);
+    }
+
+    /**
+     * Release the component from the hijacking: reenable all of its
+     * previous mouse listeners, and return the component for convenience.
+     */
+    public Component release ()
+    {
+        _comp.removeMouseMotionListener(_motionCatcher);
+
+        for (int ii=0; ii < _mls.length; ii++) {
+            _comp.addMouseListener(_mls[ii]);
+        }
+        _mls = null;
+
+        for (int ii=0; ii < _mmls.length; ii++) {
+            // fake the last movement
+            if (_lastMotion != null) {
+                _mmls[ii].mouseMoved(_lastMotion);
+            }
+            _comp.addMouseMotionListener(_mmls[ii]);
+        }
+        _mmls = null;
+
+        return _comp;
+    }
+
+    /** The component we've hijacked. */
+    protected Component _comp;
+
+    /** The last mouse moved event, captured. We're so naughty. */
+    protected MouseEvent _lastMotion;
+
+    /** Used to capture each motion event while everything's hijacked. */
+    protected MouseMotionListener _motionCatcher = new MouseMotionAdapter() {
+        public void mouseMoved (MouseEvent evt)
+        {
+            _lastMotion = evt;
+        }
+    };
+
+    /** The previous mouse listeners. */
+    protected MouseListener[] _mls;
+
+    /** The previous mouse motion listeners. */
+    protected MouseMotionListener[] _mmls;
+}