Add edgeDrag Clutter.GestureAction

This action is only triggered if started from the monitor edge specified
on construction.

js/js-resources.gresource.xml

@@ -41,6 +41,7 @@
     <file>ui/dash.js</file>
     <file>ui/dateMenu.js</file>
     <file>ui/dnd.js</file>
+    <file>ui/edgeDragAction.js</file>
     <file>ui/endSessionDialog.js</file>
     <file>ui/environment.js</file>
     <file>ui/extensionDownloader.js</file>

js/ui/edgeDragAction.js

@@ -0,0 +1,76 @@
+// -*- mode: js; js-indent-level: 4; indent-tabs-mode: nil -*-
+
+const Lang = imports.lang;
+const Signals = imports.signals;
+const Meta = imports.gi.Meta;
+const Clutter = imports.gi.Clutter;
+const St = imports.gi.St;
+
+let EDGE_THRESHOLD = 20;
+let DRAG_DISTANCE = 80;
+
+const EdgeDragAction = new Lang.Class({
+    Name: 'EdgeDragAction',
+    Extends: Clutter.GestureAction,
+
+    _init : function(side) {
+        this.parent();
+        this._side = side;
+        this.set_n_touch_points (1);
+        global.display.connect('grab-op-begin', Lang.bind(this, this.cancel));
+        global.display.connect('grab-op-end', Lang.bind(this, this.cancel));
+    },
+
+    _getMonitorRect : function (x, y) {
+        let rect = new Meta.Rectangle({ x: x - 1, y: y - 1, width: 1, height: 1 });
+        let monitorIndex = global.screen.get_monitor_index_for_rect(rect);
+
+        return global.screen.get_monitor_geometry(monitorIndex);
+    },
+
+    vfunc_gesture_prepare : function(action, actor) {
+        if (this.get_n_current_points() == 0)
+            return false;
+
+        let [x, y] = this.get_press_coords(0);
+        let monitorRect = this._getMonitorRect(x, y);
+
+        return ((this._side == St.Side.LEFT && x < monitorRect.x + EDGE_THRESHOLD) ||
+                (this._side == St.Side.RIGHT && x > monitorRect.x + monitorRect.width - EDGE_THRESHOLD) ||
+                (this._side == St.Side.TOP && y < monitorRect.y + EDGE_THRESHOLD) ||
+                (this._side == St.Side.BOTTOM && y > monitorRect.y + monitorRect.height - EDGE_THRESHOLD));
+    },
+
+    vfunc_gesture_progress : function (action, actor) {
+        let [startX, startY] = this.get_press_coords(0);
+        let [x, y] = this.get_motion_coords(0);
+        let offsetX = Math.abs (x - startX);
+        let offsetY = Math.abs (y - startY);
+
+        if (offsetX < EDGE_THRESHOLD && offsetY < EDGE_THRESHOLD)
+            return true;
+
+        if ((offsetX > offsetY &&
+             (this._side == St.Side.TOP || this._side == St.Side.BOTTOM)) ||
+            (offsetY > offsetX &&
+             (this._side == St.Side.LEFT || this._side == St.Side.RIGHT))) {
+            this.cancel();
+            return false;
+        }
+
+        return true;
+    },
+
+    vfunc_gesture_end : function (action, actor) {
+        let [startX, startY] = this.get_press_coords(0);
+        let [x, y] = this.get_motion_coords(0);
+        let monitorRect = this._getMonitorRect(startX, startY);
+
+        if ((this._side == St.Side.TOP && y > monitorRect.y + DRAG_DISTANCE) ||
+            (this._side == St.Side.BOTTOM && y < monitorRect.y + monitorRect.height - DRAG_DISTANCE) ||
+            (this._side == St.Side.LEFT && x > monitorRect.x + DRAG_DISTANCE) ||
+            (this._side == St.Side.RIGHT && x < monitorRect.x + monitorRect.width - DRAG_DISTANCE))
+            this.emit('activated');
+    }
+});
+Signals.addSignalMethods(EdgeDragAction.prototype);