gnome-shell/js/ui/dnd.js
Jasper St. Pierre 4fb33c9b09 dnd: Set the position and scale on the drag actor before it's reparented
We need to do this to ensure that it gets the correct scale, as otherwise
the transform that we retrieve will be incorrect.

https://bugzilla.gnome.org/show_bug.cgi?id=697504
2013-04-08 14:57:49 -04:00

642 lines
25 KiB
JavaScript

// -*- mode: js; js-indent-level: 4; indent-tabs-mode: nil -*-
const Clutter = imports.gi.Clutter;
const Gtk = imports.gi.Gtk;
const St = imports.gi.St;
const Lang = imports.lang;
const Shell = imports.gi.Shell;
const Signals = imports.signals;
const Tweener = imports.ui.tweener;
const Main = imports.ui.main;
const Params = imports.misc.params;
// Time to scale down to maxDragActorSize
const SCALE_ANIMATION_TIME = 0.25;
// Time to animate to original position on cancel
const SNAP_BACK_ANIMATION_TIME = 0.25;
// Time to animate to original position on success
const REVERT_ANIMATION_TIME = 0.75;
const DragMotionResult = {
NO_DROP: 0,
COPY_DROP: 1,
MOVE_DROP: 2,
CONTINUE: 3
};
const DRAG_CURSOR_MAP = {
0: Shell.Cursor.DND_UNSUPPORTED_TARGET,
1: Shell.Cursor.DND_COPY,
2: Shell.Cursor.DND_MOVE
};
const DragDropResult = {
FAILURE: 0,
SUCCESS: 1,
CONTINUE: 2
};
let eventHandlerActor = null;
let currentDraggable = null;
let dragMonitors = [];
function _getEventHandlerActor() {
if (!eventHandlerActor) {
eventHandlerActor = new Clutter.Rectangle();
eventHandlerActor.width = 0;
eventHandlerActor.height = 0;
Main.uiGroup.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 addDragMonitor(monitor) {
dragMonitors.push(monitor);
}
function removeDragMonitor(monitor) {
for (let i = 0; i < dragMonitors.length; i++)
if (dragMonitors[i] == monitor) {
dragMonitors.splice(i, 1);
return;
}
}
const _Draggable = new Lang.Class({
Name: 'Draggable',
_init : function(actor, params) {
params = Params.parse(params, { manualMode: false,
restoreOnSuccess: false,
dragActorMaxSize: undefined,
dragActorOpacity: undefined });
this.actor = actor;
if (!params.manualMode)
this.actor.connect('button-press-event',
Lang.bind(this, this._onButtonPress));
this.actor.connect('destroy', Lang.bind(this, function() {
this._actorDestroyed = true;
// If the drag actor is destroyed and we were going to fix
// up its hover state, fix up the parent hover state instead
if (this.actor == this._firstLeaveActor)
this._firstLeaveActor = this._dragOrigParent;
if (this._dragInProgress && this._dragCancellable)
this._cancelDrag(global.get_current_time());
this.disconnectAll();
}));
this._onEventId = null;
this._restoreOnSuccess = params.restoreOnSuccess;
this._dragActorMaxSize = params.dragActorMaxSize;
this._dragActorOpacity = params.dragActorOpacity;
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._animationInProgress = false; // The drag is over and the item is in the process of animating to its original position (snapping back or reverting).
this._dragCancellable = true;
// During the drag, we eat enter/leave events so that actors don't prelight.
// But we remember the actors that we first left/last entered so we can
// fix up the hover state after the drag ends.
this._firstLeaveActor = null;
this._lastEnterActor = null;
this._eventsGrabbed = false;
},
_onButtonPress : function (actor, event) {
if (event.get_button() != 1)
return false;
if (Tweener.getTweenCount(actor))
return false;
this._buttonDown = true;
this._grabActor();
let [stageX, stageY] = event.get_coords();
this._dragStartX = stageX;
this._dragStartY = stageY;
return false;
},
_grabActor: function() {
Clutter.grab_pointer(this.actor);
this._onEventId = this.actor.connect('event',
Lang.bind(this, this._onEvent));
},
_ungrabActor: function() {
if (!this._onEventId)
return;
Clutter.ungrab_pointer();
this.actor.disconnect(this._onEventId);
this._onEventId = null;
},
_grabEvents: function() {
if (!this._eventsGrabbed) {
Clutter.grab_pointer(_getEventHandlerActor());
Clutter.grab_keyboard(_getEventHandlerActor());
this._eventsGrabbed = true;
}
},
_ungrabEvents: function() {
if (this._eventsGrabbed) {
Clutter.ungrab_pointer();
Clutter.ungrab_keyboard();
this._eventsGrabbed = false;
}
},
_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._animationInProgress) {
// 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;
}
} else if (event.type() == Clutter.EventType.LEAVE) {
if (this._firstLeaveActor == null)
this._firstLeaveActor = event.get_source();
} else if (event.type() == Clutter.EventType.ENTER) {
this._lastEnterActor = event.get_source();
}
return false;
},
/**
* fakeRelease:
*
* Fake a release event.
* Must be called if you want to intercept release events on draggable
* actors for other purposes (for example if you're using
* PopupMenu.ignoreRelease())
*/
fakeRelease: function() {
this._buttonDown = false;
this._ungrabActor();
},
/**
* startDrag:
* @stageX: X coordinate of event
* @stageY: Y coordinate of event
* @time: Event timestamp
*
* Directly initiate a drag and drop operation from the given actor.
* This function is useful to call if you've specified manualMode
* for the draggable.
*/
startDrag: function (stageX, stageY, time) {
currentDraggable = this;
this._dragInProgress = true;
// Special-case St.Button: the pointer grab messes with the internal
// state, so force a reset to a reasonable state here
if (this.actor instanceof St.Button) {
this.actor.fake_release();
this.actor.hover = false;
}
this.emit('drag-begin', time);
if (this._onEventId)
this._ungrabActor();
this._grabEvents();
global.set_cursor(Shell.Cursor.DND_IN_DRAG);
this._dragX = this._dragStartX = stageX;
this._dragY = this._dragStartY = stageY;
if (this.actor._delegate && this.actor._delegate.getDragActor) {
this._dragActor = this.actor._delegate.getDragActor();
this._dragActor.reparent(Main.uiGroup);
this._dragActor.raise_top();
Shell.util_set_hidden_from_pick(this._dragActor, true);
// Drag actor does not always have to be the same as actor. For example drag actor
// can be an image that's part of the actor. So to perform "snap back" correctly we need
// to know what was the drag actor source.
if (this.actor._delegate.getDragActorSource) {
this._dragActorSource = this.actor._delegate.getDragActorSource();
// If the user dragged from the source, then position
// the dragActor over it. Otherwise, center it
// around the pointer
let [sourceX, sourceY] = this._dragActorSource.get_transformed_position();
let x, y;
if (stageX > sourceX && stageX <= sourceX + this._dragActor.width &&
stageY > sourceY && stageY <= sourceY + this._dragActor.height) {
x = sourceX;
y = sourceY;
} else {
x = stageX - this._dragActor.width / 2;
y = stageY - this._dragActor.height / 2;
}
this._dragActor.set_position(x, y);
} else {
this._dragActorSource = this.actor;
}
this._dragOrigParent = undefined;
this._dragOffsetX = this._dragActor.x - this._dragStartX;
this._dragOffsetY = this._dragActor.y - this._dragStartY;
} else {
this._dragActor = this.actor;
this._dragActorSource = undefined;
this._dragOrigParent = this.actor.get_parent();
this._dragOrigX = this._dragActor.x;
this._dragOrigY = this._dragActor.y;
this._dragOrigScale = this._dragActor.scale_x;
// Set the actor's scale such that it will keep the same
// transformed size when it's reparented to the uiGroup
let [scaledWidth, scaledHeight] = this.actor.get_transformed_size();
this._dragActor.set_scale(scaledWidth / this.actor.width,
scaledHeight / this.actor.height);
let [actorStageX, actorStageY] = this.actor.get_transformed_position();
this._dragOffsetX = actorStageX - this._dragStartX;
this._dragOffsetY = actorStageY - this._dragStartY;
this._dragActor.reparent(Main.uiGroup);
this._dragActor.raise_top();
Shell.util_set_hidden_from_pick(this._dragActor, true);
}
this._dragOrigOpacity = this._dragActor.opacity;
if (this._dragActorOpacity != undefined)
this._dragActor.opacity = this._dragActorOpacity;
this._snapBackX = this._dragStartX + this._dragOffsetX;
this._snapBackY = this._dragStartY + this._dragOffsetY;
this._snapBackScale = this._dragActor.scale_x;
if (this._dragActorMaxSize != undefined) {
let [scaledWidth, scaledHeight] = this._dragActor.get_transformed_size();
let currentSize = Math.max(scaledWidth, scaledHeight);
if (currentSize > this._dragActorMaxSize) {
let scale = this._dragActorMaxSize / currentSize;
let origScale = this._dragActor.scale_x;
let origDragOffsetX = this._dragOffsetX;
let origDragOffsetY = this._dragOffsetY;
// The position of the actor changes as we scale
// around the drag position, but we can't just tween
// to the final position because that tween would
// fight with updates as the user continues dragging
// the mouse; instead we do the position computations in
// an onUpdate() function.
Tweener.addTween(this._dragActor,
{ scale_x: scale * origScale,
scale_y: scale * origScale,
time: SCALE_ANIMATION_TIME,
transition: 'easeOutQuad',
onUpdate: function() {
let currentScale = this._dragActor.scale_x / origScale;
this._dragOffsetX = currentScale * origDragOffsetX;
this._dragOffsetY = currentScale * origDragOffsetY;
this._dragActor.set_position(this._dragX + this._dragOffsetX,
this._dragY + this._dragOffsetY);
},
onUpdateScope: this });
}
}
},
_maybeStartDrag: function(event) {
let [stageX, stageY] = event.get_coords();
// See if the user has moved the mouse enough to trigger a drag
let threshold = Gtk.Settings.get_default().gtk_dnd_drag_threshold;
if ((Math.abs(stageX - this._dragStartX) > threshold ||
Math.abs(stageY - this._dragStartY) > threshold)) {
this.startDrag(stageX, stageY, event.get_time());
this._updateDragPosition(event);
}
return true;
},
_updateDragPosition : function (event) {
let [stageX, stageY] = event.get_coords();
this._dragX = stageX;
this._dragY = stageY;
// If we are dragging, update the position
if (this._dragActor) {
this._dragActor.set_position(stageX + this._dragOffsetX,
stageY + this._dragOffsetY);
let target = this._dragActor.get_stage().get_actor_at_pos(Clutter.PickMode.ALL,
stageX, stageY);
// We call observers only once per motion with the innermost
// target actor. If necessary, the observer can walk the
// parent itself.
let dragEvent = {
x: stageX,
y: stageY,
dragActor: this._dragActor,
source: this.actor._delegate,
targetActor: target
};
for (let i = 0; i < dragMonitors.length; i++) {
let motionFunc = dragMonitors[i].dragMotion;
if (motionFunc) {
let result = motionFunc(dragEvent);
if (result != DragMotionResult.CONTINUE) {
global.set_cursor(DRAG_CURSOR_MAP[result]);
return true;
}
}
}
while (target) {
if (target._delegate && target._delegate.handleDragOver) {
let [r, targX, targY] = target.transform_stage_point(stageX, stageY);
// 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.
let result = target._delegate.handleDragOver(this.actor._delegate,
this._dragActor,
targX,
targY,
event.get_time());
if (result != DragMotionResult.CONTINUE) {
global.set_cursor(DRAG_CURSOR_MAP[result]);
return true;
}
}
target = target.get_parent();
}
global.set_cursor(Shell.Cursor.DND_IN_DRAG);
}
return true;
},
_dragActorDropped: function(event) {
let [dropX, dropY] = event.get_coords();
let target = this._dragActor.get_stage().get_actor_at_pos(Clutter.PickMode.ALL,
dropX, dropY);
// We call observers only once per motion with the innermost
// target actor. If necessary, the observer can walk the
// parent itself.
let dropEvent = {
dropActor: this._dragActor,
targetActor: target,
clutterEvent: event
};
for (let i = 0; i < dragMonitors.length; i++) {
let dropFunc = dragMonitors[i].dragDrop;
if (dropFunc)
switch (dropFunc(dropEvent)) {
case DragDropResult.FAILURE:
case DragDropResult.SUCCESS:
return true;
case DragDropResult.CONTINUE:
continue;
}
}
// At this point it is too late to cancel a drag by destroying
// the actor, the fate of which is decided by acceptDrop and its
// side-effects
this._dragCancellable = false;
while (target) {
if (target._delegate && target._delegate.acceptDrop) {
let [r, targX, targY] = target.transform_stage_point(dropX, dropY);
if (target._delegate.acceptDrop(this.actor._delegate,
this._dragActor,
targX,
targY,
event.get_time())) {
// If it accepted the drop without taking the actor,
// handle it ourselves.
if (this._dragActor.get_parent() == Main.uiGroup) {
if (this._restoreOnSuccess) {
this._restoreDragActor(event.get_time());
return true;
} else
this._dragActor.destroy();
}
this._dragInProgress = false;
global.unset_cursor();
this.emit('drag-end', event.get_time(), true);
this._dragComplete();
return true;
}
}
target = target.get_parent();
}
this._cancelDrag(event.get_time());
return true;
},
_getRestoreLocation: function() {
let x, y, scale;
if (this._dragActorSource && this._dragActorSource.visible) {
// Snap the clone back to its source
[x, y] = this._dragActorSource.get_transformed_position();
let [sourceScaledWidth, sourceScaledHeight] = this._dragActorSource.get_transformed_size();
scale = this._dragActor.width / sourceScaledWidth;
} else if (this._dragOrigParent) {
// Snap the actor back to its original position within
// its parent, adjusting for the fact that the parent
// may have been moved or scaled
let [parentX, parentY] = this._dragOrigParent.get_transformed_position();
let [parentWidth, parentHeight] = this._dragOrigParent.get_size();
let [parentScaledWidth, parentScaledHeight] = this._dragOrigParent.get_transformed_size();
let parentScale = 1.0;
if (parentWidth != 0)
parentScale = parentScaledWidth / parentWidth;
x = parentX + parentScale * this._dragOrigX;
y = parentY + parentScale * this._dragOrigY;
scale = this._dragOrigScale * parentScale;
} else {
// Snap back actor to its original stage position
x = this._snapBackX;
y = this._snapBackY;
scale = this._snapBackScale;
}
return [x, y, scale];
},
_cancelDrag: function(eventTime) {
this.emit('drag-cancelled', eventTime);
this._dragInProgress = false;
let [snapBackX, snapBackY, snapBackScale] = this._getRestoreLocation();
if (this._actorDestroyed) {
global.unset_cursor();
if (!this._buttonDown)
this._dragComplete();
this.emit('drag-end', eventTime, false);
if (!this._dragOrigParent)
this._dragActor.destroy();
return;
}
this._animationInProgress = true;
// No target, so snap back
Tweener.addTween(this._dragActor,
{ x: snapBackX,
y: snapBackY,
scale_x: snapBackScale,
scale_y: snapBackScale,
opacity: this._dragOrigOpacity,
time: SNAP_BACK_ANIMATION_TIME,
transition: 'easeOutQuad',
onComplete: this._onAnimationComplete,
onCompleteScope: this,
onCompleteParams: [this._dragActor, eventTime]
});
},
_restoreDragActor: function(eventTime) {
this._dragInProgress = false;
[restoreX, restoreY, restoreScale] = this._getRestoreLocation();
// fade the actor back in at its original location
this._dragActor.set_position(restoreX, restoreY);
this._dragActor.set_scale(restoreScale, restoreScale);
this._dragActor.opacity = 0;
this._animationInProgress = true;
Tweener.addTween(this._dragActor,
{ opacity: this._dragOrigOpacity,
time: REVERT_ANIMATION_TIME,
transition: 'easeOutQuad',
onComplete: this._onAnimationComplete,
onCompleteScope: this,
onCompleteParams: [this._dragActor, eventTime]
});
},
_onAnimationComplete : function (dragActor, eventTime) {
if (this._dragOrigParent) {
dragActor.reparent(this._dragOrigParent);
dragActor.set_scale(this._dragOrigScale, this._dragOrigScale);
dragActor.set_position(this._dragOrigX, this._dragOrigY);
} else {
dragActor.destroy();
}
global.unset_cursor();
this.emit('drag-end', eventTime, false);
this._animationInProgress = false;
if (!this._buttonDown)
this._dragComplete();
},
// Actor is an actor we have entered or left during the drag; call
// st_widget_sync_hover on all StWidget ancestors
_syncHover: function(actor) {
while (actor) {
let parent = actor.get_parent();
if (actor instanceof St.Widget)
actor.sync_hover();
actor = parent;
}
},
_dragComplete: function() {
if (!this._actorDestroyed)
Shell.util_set_hidden_from_pick(this._dragActor, false);
this._ungrabEvents();
if (this._firstLeaveActor) {
this._syncHover(this._firstLeaveActor);
this._firstLeaveActor = null;
}
if (this._lastEnterActor) {
this._syncHover(this._lastEnterActor);
this._lastEnterActor = null;
}
this._dragActor = undefined;
currentDraggable = null;
}
});
Signals.addSignalMethods(_Draggable.prototype);
/**
* makeDraggable:
* @actor: Source actor
* @params: (optional) Additional parameters
*
* Create an object which controls drag and drop for the given actor.
*
* If %manualMode is %true in @params, do not automatically start
* drag and drop on click
*
* If %dragActorMaxSize is present in @params, the drag actor will
* be scaled down to be no larger than that size in pixels.
*
* If %dragActorOpacity is present in @params, the drag actor will
* will be set to have that opacity during the drag.
*
* Note that when the drag actor is the source actor and the drop
* succeeds, the actor scale and opacity aren't reset; if the drop
* target wants to reuse the actor, it's up to the drop target to
* reset these values.
*/
function makeDraggable(actor, params) {
return new _Draggable(actor, params);
}