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Bug 594916 - Allow cancelling DND by hitting Esc

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Esc used to close the overview and get the DND actor stuck on the desktop when
it was pressed when dragging.
This commit is contained in:
Marina Zhurakhinskaya 2009-09-22 16:15:28 -04:00
parent 0918bdd612
commit 6cae94edcc
2 changed files with 142 additions and 73 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
js/ui/appDisplay.js
View File

@ -781,7 +781,7 @@ BaseWellItem.prototype = {
if (!hover) {
if (this.actor.pressed && this._dragStartX != null) {
this.actor.fake_release();
this._draggable.startDrag(this.icon.actor, this._dragStartX, this._dragStartY,
this._draggable.startDrag(this._dragStartX, this._dragStartY,
Clutter.get_current_event_time());
} else {
this._dragStartX = null;

201
js/ui/dnd.js
View File

@ -8,6 +8,25 @@ const Tweener = imports.ui.tweener;
const SNAP_BACK_ANIMATION_TIME = 0.25;
let eventHandlerActor = null;
let currentDraggable = null;
function _getEventHandlerActor() {
if (!eventHandlerActor) {
eventHandlerActor = new Clutter.Rectangle();
eventHandlerActor.width = 0;
eventHandlerActor.height = 0;
global.stage.add_actor(eventHandlerActor);
// We connect to 'event' rather than 'captured-event' because the capturing phase doesn't happen
// when you've grabbed the pointer.
eventHandlerActor.connect('event',
function(actor, event) {
return currentDraggable._onEvent(actor, event);
});
}
return eventHandlerActor;
}
function _Draggable(actor, manualMode) {
this._init(actor, manualMode);
}
@ -18,7 +37,11 @@ _Draggable.prototype = {
if (!manualMode)
this.actor.connect('button-press-event',
Lang.bind(this, this._onButtonPress));
this._haveSourceGrab = false;
this._onEventId = null;
this._buttonDown = false; // The mouse button has been pressed and has not yet been released.
this._dragInProgress = false; // The drag has been started, and has not been dropped or cancelled yet.
this._snapBackInProgress = false; // The drag has been cancelled and the item is in the process of snapping back.
},
_onButtonPress : function (actor, event) {
@ -27,8 +50,8 @@ _Draggable.prototype = {
if (Tweener.getTweenCount(actor))
return false;
this._haveSourceGrab = true;
this._grabActor(actor);
this._buttonDown = true;
this._grabActor();
let [stageX, stageY] = event.get_coords();
this._dragStartX = stageX;
@ -37,41 +60,69 @@ _Draggable.prototype = {
return false;
},
_grabActor : function (actor) {
Clutter.grab_pointer(actor);
// We intercept motion and button-release events so that when
// you release after dragging, the app doesn't see that and
// think you just clicked. We connect to 'event' rather than
// 'captured-event' because the capturing phase doesn't happen
// when you've grabbed the pointer.
this._onEventId = actor.connect('event',
_grabActor: function() {
Clutter.grab_pointer(this.actor);
this._onEventId = this.actor.connect('event',
Lang.bind(this, this._onEvent));
},
_ungrabActor : function (actor) {
_ungrabActor: function() {
Clutter.ungrab_pointer();
actor.disconnect(this._onEventId);
this.actor.disconnect(this._onEventId);
this._onEventId = null;
},
_onEvent : function (actor, event) {
if (this._dragActor) {
if (actor != this._dragActor )
return false;
} else if (actor != this.actor)
return false;
_grabEvents: function() {
Clutter.grab_pointer(_getEventHandlerActor());
Clutter.grab_keyboard(_getEventHandlerActor());
},
_ungrabEvents: function() {
Clutter.ungrab_pointer();
Clutter.ungrab_keyboard();
},
_onEvent: function(actor, event) {
// We intercept BUTTON_RELEASE event to know that the button was released in case we
// didn't start the drag, to drop the draggable in case the drag was in progress, and
// to complete the drag and ensure that whatever happens to be under the pointer does
// not get triggered if the drag was cancelled with Esc.
if (event.type() == Clutter.EventType.BUTTON_RELEASE) {
this._buttonDown = false;
if (this._dragInProgress) {
return this._dragActorDropped(event);
} else if (this._dragActor != null && !this._snapBackInProgress) {
// Drag must have been cancelled with Esc.
this._dragComplete();
return true;
} else {
// Drag has never started.
this._ungrabActor();
return false;
}
// We intercept MOTION event to figure out if the drag has started and to draw
// this._dragActor under the pointer when dragging is in progress
} else if (event.type() == Clutter.EventType.MOTION) {
if (this._dragInProgress) {
return this._updateDragPosition(event);
} else if (this._dragActor == null) {
return this._maybeStartDrag(event);
}
// We intercept KEY_PRESS event so that we can process Esc key press to cancel
// dragging and ignore all other key presses.
} else if (event.type() == Clutter.EventType.KEY_PRESS && this._dragInProgress) {
let symbol = event.get_key_symbol();
if (symbol == Clutter.Escape) {
this._cancelDrag(event.get_time());
return true;
}
}
if (event.type() == Clutter.EventType.BUTTON_RELEASE)
return this._onButtonRelease(actor, event);
else if (event.type() == Clutter.EventType.MOTION)
return this._onMotion(actor, event);
else
return false;
},
/**
* startDrag:
* @actor: Origin actor for drag and drop
* @stageX: X coordinate of event
* @stageY: Y coordinate of event
* @time: Event timestamp
@ -80,8 +131,14 @@ _Draggable.prototype = {
* This function is useful to call if you've specified manualMode
* for the draggable.
*/
startDrag: function (actor, stageX, stageY, time) {
startDrag: function (stageX, stageY, time) {
currentDraggable = this;
this._dragInProgress = true;
this.emit('drag-begin', time);
if (this._onEventId)
this._ungrabActor();
this._grabEvents();
this._dragStartX = stageX;
this._dragStartY = stageY;
@ -112,49 +169,49 @@ _Draggable.prototype = {
this._dragActorSource = this.actor;
}
this._dragOrigParent = undefined;
if (this._haveSourceGrab) {
this._haveSourceGrab = false;
this._ungrabActor(actor);
}
this._grabActor(this._dragActor);
this._dragOffsetX = this._dragActor.x - this._dragStartX;
this._dragOffsetY = this._dragActor.y - this._dragStartY;
} else {
this._dragActor = actor;
this._dragActor = this.actor;
this._dragActorSource = undefined;
this._dragOrigParent = actor.get_parent();
this._dragOrigParent = this.actor.get_parent();
this._dragOrigX = this._dragActor.x;
this._dragOrigY = this._dragActor.y;
this._dragOrigScale = this._dragActor.scale_x;
let [actorStageX, actorStageY] = actor.get_transformed_position();
let [actorStageX, actorStageY] = this.actor.get_transformed_position();
this._dragOffsetX = actorStageX - this._dragStartX;
this._dragOffsetY = actorStageY - this._dragStartY;
// Set the actor's scale such that it will keep the same
// transformed size when it's reparented to the stage
let [scaledWidth, scaledHeight] = actor.get_transformed_size();
actor.set_scale(scaledWidth / actor.width,
scaledHeight / actor.height);
let [scaledWidth, scaledHeight] = this.actor.get_transformed_size();
this.actor.set_scale(scaledWidth / this.actor.width,
scaledHeight / this.actor.height);
}
this._dragActor.reparent(actor.get_stage());
this._dragActor.reparent(this.actor.get_stage());
this._dragActor.raise_top();
},
_onMotion : function (actor, event) {
_maybeStartDrag: function(event) {
let [stageX, stageY] = event.get_coords();
// If we haven't begun a drag, see if the user has moved the
// mouse enough to trigger a drag
// See if the user has moved the mouse enough to trigger a drag
let threshold = Gtk.Settings.get_default().gtk_dnd_drag_threshold;
if (!this._dragActor &&
(Math.abs(stageX - this._dragStartX) > threshold ||
if ((Math.abs(stageX - this._dragStartX) > threshold ||
Math.abs(stageY - this._dragStartY) > threshold)) {
this.startDrag(actor, stageX, stageY, event.get_time());
this.startDrag(stageX, stageY, event.get_time());
this._updateDragPosition(event);
}
return true;
},
_updateDragPosition : function (event) {
let [stageX, stageY] = event.get_coords();
// If we are dragging, update the position
if (this._dragActor) {
this._dragActor.set_position(stageX + this._dragOffsetX,
@ -162,7 +219,7 @@ _Draggable.prototype = {
// Because we want to find out what other actor is located at the current position of this._dragActor,
// we have to temporarily hide this._dragActor.
this._dragActor.hide();
let target = actor.get_stage().get_actor_at_pos(Clutter.PickMode.ALL,
let target = this._dragActor.get_stage().get_actor_at_pos(Clutter.PickMode.ALL,
stageX + this._dragOffsetX,
stageY + this._dragOffsetY);
this._dragActor.show();
@ -172,7 +229,7 @@ _Draggable.prototype = {
// We currently loop through all parents on drag-over even if one of the children has handled it.
// We can check the return value of the function and break the loop if it's true if we don't want
// to continue checking the parents.
target._delegate.handleDragOver(this.actor._delegate, actor,
target._delegate.handleDragOver(this.actor._delegate, this._dragActor,
(stageX + this._dragOffsetX - targX) / target.scale_x,
(stageY + this._dragOffsetY - targY) / target.scale_y,
event.get_time());
@ -184,40 +241,42 @@ _Draggable.prototype = {
return true;
},
_onButtonRelease : function (actor, event) {
this._ungrabActor(actor);
let dragging = (actor == this._dragActor);
this._dragActor = undefined;
if (!dragging)
return false;
// Find a drop target
actor.hide();
_dragActorDropped: function(event) {
// Find a drop target. Because we want to find out what other actor is located at
// the current position of this._dragActor, we have to temporarily hide this._dragActor.
this._dragActor.hide();
let [dropX, dropY] = event.get_coords();
let target = actor.get_stage().get_actor_at_pos(Clutter.PickMode.ALL,
let target = this._dragActor.get_stage().get_actor_at_pos(Clutter.PickMode.ALL,
dropX, dropY);
actor.show();
this._dragActor.show();
while (target) {
if (target._delegate && target._delegate.acceptDrop) {
let [targX, targY] = target.get_transformed_position();
if (target._delegate.acceptDrop(this.actor._delegate, actor,
if (target._delegate.acceptDrop(this.actor._delegate, this._dragActor,
(dropX - targX) / target.scale_x,
(dropY - targY) / target.scale_y,
event.get_time())) {
// If it accepted the drop without taking the actor,
// destroy it.
if (actor.get_parent() == actor.get_stage())
actor.destroy();
if (this._dragActor.get_parent() == this._dragActor.get_stage())
this._dragActor.destroy();
this._dragInProgress = false;
this.emit('drag-end', event.get_time(), true);
this._dragComplete();
return true;
}
}
target = target.get_parent();
}
this._cancelDrag(event.get_time());
return true;
},
_cancelDrag: function(eventTime) {
this._dragInProgress = false;
// Snap back to the actor source if the source is still around, snap back
// to the original location if the actor itself was being dragged or the
// source is no longer around.
@ -227,17 +286,17 @@ _Draggable.prototype = {
[snapBackX, snapBackY] = this._dragActorSource.get_transformed_position();
}
this._snapBackInProgress = true;
// No target, so snap back
Tweener.addTween(actor,
Tweener.addTween(this._dragActor,
{ x: snapBackX,
y: snapBackY,
time: SNAP_BACK_ANIMATION_TIME,
transition: "easeOutQuad",
onComplete: this._onSnapBackComplete,
onCompleteScope: this,
onCompleteParams: [actor, event.get_time()]
onCompleteParams: [this._dragActor, eventTime]
});
return true;
},
_onSnapBackComplete : function (dragActor, eventTime) {
@ -249,6 +308,16 @@ _Draggable.prototype = {
dragActor.destroy();
}
this.emit('drag-end', eventTime, false);
this._snapBackInProgress = false;
if (!this._buttonDown)
this._dragComplete();
},
_dragComplete: function() {
this._dragActor = undefined;
currentDraggable = null;
this._ungrabEvents();
}
};