1 files changed, 156 insertions, 0 deletions
diff --git a/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gle2/Gesture.java b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gle2/Gesture.java
new file mode 100644
index 000000000..a35d19078
--- /dev/null
+++ b/eclipse/plugins/com.android.ide.eclipse.adt/src/com/android/ide/eclipse/adt/internal/editors/layout/gle2/Gesture.java
@@ -0,0 +1,156 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Eclipse Public License, Version 1.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.eclipse.org/org/documents/epl-v10.php
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.ide.eclipse.adt.internal.editors.layout.gle2;
+
+import com.android.utils.Pair;
+
+import org.eclipse.swt.events.KeyEvent;
+
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * A gesture is a mouse or keyboard driven user operation, such as a
+ * swipe-select or a resize. It can be thought of as a session, since it is
+ * initiated, updated during user manipulation, and finally completed or
+ * canceled. A gesture is associated with a single undo transaction (although
+ * some gestures don't actually edit anything, such as a selection), and a
+ * gesture can have a number of graphics {@link Overlay}s which are added and
+ * cleaned up on behalf of the gesture by the system.
+ * <p/>
+ * Gestures are typically mouse oriented. If a mouse wishes to integrate
+ * with the native drag &amp; drop support, it should also implement
+ * the {@link DropGesture} interface, which is a sub interface of this
+ * {@link Gesture} interface. There are pros and cons to using native drag
+ * &amp; drop, so various gestures will differ in whether they use it.
+ * In particular, you should use drag &amp; drop if your gesture should:
+ * <ul>
+ * <li> Show a native drag &amp; drop cursor
+ * <li> Copy or move data, especially if this applies outside the canvas
+ *    control window or even the application itself
+ * </ul>
+ * You might want to avoid using native drag &amp; drop if your gesture should:
+ * <ul>
+ * <li> Continue updating itself even when the mouse cursor leaves the
+ *    canvas window (in a drag &amp; gesture, as soon as you leave the canvas
+ *    the drag source is no longer informed of mouse updates, whereas a regular
+ *    mouse listener is)
+ * <li> Respond to modifier keys (for example, if toggling the Shift key
+ *    should constrain motion as is common during resizing, and so on)
+ * <li> Use no special cursor (for example, during a marquee selection gesture we
+ *     don't want a native drag &amp; drop cursor)
+ *  </ul>
+ * <p/>
+ * Examples of gestures:
+ * <ul>
+ * <li>Move (dragging to reorder or change hierarchy of views or change visual
+ * layout attributes)
+ * <li>Marquee (swiping out a rectangle to make a selection)
+ * <li>Resize (dragging some edge or corner of a widget to change its size, for
+ * example to some new fixed size, or to "attach" it to some other edge.)
+ * <li>Inline Editing (editing the text of some text-oriented widget like a
+ * label or a button)
+ * <li>Link (associate two or more widgets in some way, such as an
+ *   "is required" widget linked to a text field)
+ * </ul>
+ */
+public abstract class Gesture {
+    /** Start mouse coordinate, in control coordinates. */
+    protected ControlPoint mStart;
+
+    /** Initial SWT mask when the gesture started. */
+    protected int mStartMask;
+
+    /**
+     * Returns a list of overlays, from bottom to top (where the later overlays
+     * are painted on top of earlier ones if they overlap).
+     *
+     * @return A list of overlays to paint for this gesture, if applicable.
+     *         Should not be null, but can be empty.
+     */
+    public List<Overlay> createOverlays() {
+        return Collections.emptyList();
+    }
+
+    /**
+     * Handles initialization of this gesture. Called when the gesture is
+     * starting.
+     *
+     * @param pos The most recent mouse coordinate applicable to this
+     *            gesture, relative to the canvas control.
+     * @param startMask The initial SWT mask for the gesture, if known, or
+     *            otherwise 0.
+     */
+    public void begin(ControlPoint pos, int startMask) {
+        mStart = pos;
+        mStartMask = startMask;
+    }
+
+    /**
+     * Handles updating of the gesture state for a new mouse position.
+     *
+     * @param pos The most recent mouse coordinate applicable to this
+     *            gesture, relative to the canvas control.
+     */
+    public void update(ControlPoint pos) {
+    }
+
+    /**
+     * Handles termination of the gesture. This method is called when the
+     * gesture has terminated (either through successful completion, or because
+     * it was canceled).
+     *
+     * @param pos The most recent mouse coordinate applicable to this
+     *            gesture, relative to the canvas control.
+     * @param canceled True if the gesture was canceled, and false otherwise.
+     */
+    public void end(ControlPoint pos, boolean canceled) {
+    }
+
+    /**
+     * Handles a key press during the gesture. May be called repeatedly when the
+     * user is holding the key for several seconds.
+     *
+     * @param event The SWT event for the key press,
+     * @return true if this gesture consumed the key press, otherwise return false
+     */
+    public boolean keyPressed(KeyEvent event) {
+        return false;
+    }
+
+    /**
+     * Handles a key release during the gesture.
+     *
+     * @param event The SWT event for the key release,
+     * @return true if this gesture consumed the key press, otherwise return false
+     */
+    public boolean keyReleased(KeyEvent event) {
+        return false;
+    }
+
+    /**
+     * Returns whether tooltips should be display below and to the right of the mouse
+     * cursor.
+     *
+     * @return a pair of booleans, the first indicating whether the tooltip should be
+     *         below and the second indicating whether the tooltip should be displayed to
+     *         the right of the mouse cursor.
+     */
+    public Pair<Boolean, Boolean> getTooltipPosition() {
+        return Pair.of(true, true);
+    }
+}