diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 15:07:22 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 15:07:22 +0000 |
commit | f9d480cfe50ca1d7a0f0b5a2b8bb9932962bfbe7 (patch) | |
tree | ce9e8db2d4e8799780fa72ae8f1953039373e2ee /js/ui/grabHelper.js | |
parent | Initial commit. (diff) | |
download | gnome-shell-upstream/3.38.6.tar.xz gnome-shell-upstream/3.38.6.zip |
Adding upstream version 3.38.6.upstream/3.38.6upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | js/ui/grabHelper.js | 332 |
1 files changed, 332 insertions, 0 deletions
diff --git a/js/ui/grabHelper.js b/js/ui/grabHelper.js new file mode 100644 index 0000000..2ba2aad --- /dev/null +++ b/js/ui/grabHelper.js @@ -0,0 +1,332 @@ +// -*- mode: js; js-indent-level: 4; indent-tabs-mode: nil -*- +/* exported GrabHelper */ + +const { Clutter, St } = imports.gi; + +const Main = imports.ui.main; +const Params = imports.misc.params; + +let _capturedEventId = 0; +let _grabHelperStack = []; +function _onCapturedEvent(actor, event) { + let grabHelper = _grabHelperStack[_grabHelperStack.length - 1]; + return grabHelper.onCapturedEvent(event); +} + +function _pushGrabHelper(grabHelper) { + _grabHelperStack.push(grabHelper); + + if (_capturedEventId == 0) + _capturedEventId = global.stage.connect('captured-event', _onCapturedEvent); +} + +function _popGrabHelper(grabHelper) { + let poppedHelper = _grabHelperStack.pop(); + if (poppedHelper != grabHelper) + throw new Error("incorrect grab helper pop"); + + if (_grabHelperStack.length == 0) { + global.stage.disconnect(_capturedEventId); + _capturedEventId = 0; + } +} + +// GrabHelper: +// @owner: the actor that owns the GrabHelper +// @params: optional parameters to pass to Main.pushModal() +// +// Creates a new GrabHelper object, for dealing with keyboard and pointer grabs +// associated with a set of actors. +// +// Note that the grab can be automatically dropped at any time by the user, and +// your code just needs to deal with it; you shouldn't adjust behavior directly +// after you call ungrab(), but instead pass an 'onUngrab' callback when you +// call grab(). +var GrabHelper = class GrabHelper { + constructor(owner, params) { + if (!(owner instanceof Clutter.Actor)) + throw new Error('GrabHelper owner must be a Clutter.Actor'); + + this._owner = owner; + this._modalParams = params; + + this._grabStack = []; + + this._actors = []; + this._ignoreUntilRelease = false; + + this._modalCount = 0; + } + + // addActor: + // @actor: an actor + // + // Adds @actor to the set of actors that are allowed to process events + // during a grab. + addActor(actor) { + actor.__grabHelperDestroyId = actor.connect('destroy', () => { + this.removeActor(actor); + }); + this._actors.push(actor); + } + + // removeActor: + // @actor: an actor + // + // Removes @actor from the set of actors that are allowed to + // process events during a grab. + removeActor(actor) { + let index = this._actors.indexOf(actor); + if (index != -1) + this._actors.splice(index, 1); + if (actor.__grabHelperDestroyId) { + actor.disconnect(actor.__grabHelperDestroyId); + delete actor.__grabHelperDestroyId; + } + } + + _isWithinGrabbedActor(actor) { + let currentActor = this.currentGrab.actor; + while (actor) { + if (this._actors.includes(actor)) + return true; + if (actor == currentActor) + return true; + actor = actor.get_parent(); + } + return false; + } + + get currentGrab() { + return this._grabStack[this._grabStack.length - 1] || {}; + } + + get grabbed() { + return this._grabStack.length > 0; + } + + get grabStack() { + return this._grabStack; + } + + _findStackIndex(actor) { + if (!actor) + return -1; + + for (let i = 0; i < this._grabStack.length; i++) { + if (this._grabStack[i].actor === actor) + return i; + } + return -1; + } + + _actorInGrabStack(actor) { + while (actor) { + let idx = this._findStackIndex(actor); + if (idx >= 0) + return idx; + actor = actor.get_parent(); + } + return -1; + } + + isActorGrabbed(actor) { + return this._findStackIndex(actor) >= 0; + } + + // grab: + // @params: A bunch of parameters, see below + // + // The general effect of a "grab" is to ensure that the passed in actor + // and all actors inside the grab get exclusive control of the mouse and + // keyboard, with the grab automatically being dropped if the user tries + // to dismiss it. The actor is passed in through @params.actor. + // + // grab() can be called multiple times, with the scope of the grab being + // changed to a different actor every time. A nested grab does not have + // to have its grabbed actor inside the parent grab actors. + // + // Grabs can be automatically dropped if the user tries to dismiss it + // in one of two ways: the user clicking outside the currently grabbed + // actor, or the user typing the Escape key. + // + // If the user clicks outside the grabbed actors, and the clicked on + // actor is part of a previous grab in the stack, grabs will be popped + // until that grab is active. However, the click event will not be + // replayed to the actor. + // + // If the user types the Escape key, one grab from the grab stack will + // be popped. + // + // When a grab is popped by user interacting as described above, if you + // pass a callback as @params.onUngrab, it will be called with %true. + // + // If @params.focus is not null, we'll set the key focus directly + // to that actor instead of navigating in @params.actor. This is for + // use cases like menus, where we want to grab the menu actor, but keep + // focus on the clicked on menu item. + grab(params) { + params = Params.parse(params, { actor: null, + focus: null, + onUngrab: null }); + + let focus = global.stage.key_focus; + let hadFocus = focus && this._isWithinGrabbedActor(focus); + let newFocus = params.actor; + + if (this.isActorGrabbed(params.actor)) + return true; + + params.savedFocus = focus; + + if (!this._takeModalGrab()) + return false; + + this._grabStack.push(params); + + if (params.focus) { + params.focus.grab_key_focus(); + } else if (newFocus && hadFocus) { + if (!newFocus.navigate_focus(null, St.DirectionType.TAB_FORWARD, false)) + newFocus.grab_key_focus(); + } + + return true; + } + + grabAsync(params) { + return new Promise((resolve, reject) => { + params.onUngrab = resolve; + + if (!this.grab(params)) + reject(new Error('Grab failed')); + }); + } + + _takeModalGrab() { + let firstGrab = this._modalCount == 0; + if (firstGrab) { + if (!Main.pushModal(this._owner, this._modalParams)) + return false; + + _pushGrabHelper(this); + } + + this._modalCount++; + return true; + } + + _releaseModalGrab() { + this._modalCount--; + if (this._modalCount > 0) + return; + + _popGrabHelper(this); + + this._ignoreUntilRelease = false; + + Main.popModal(this._owner); + global.sync_pointer(); + } + + // ignoreRelease: + // + // Make sure that the next button release event evaluated by the + // capture event handler returns false. This is designed for things + // like the ComboBoxMenu that go away on press, but need to eat + // the next release event. + ignoreRelease() { + this._ignoreUntilRelease = true; + } + + // ungrab: + // @params: The parameters for the grab; see below. + // + // Pops @params.actor from the grab stack, potentially dropping + // the grab. If the actor is not on the grab stack, this call is + // ignored with no ill effects. + // + // If the actor is not at the top of the grab stack, grabs are + // popped until the grabbed actor is at the top of the grab stack. + // The onUngrab callback for every grab is called for every popped + // grab with the parameter %false. + ungrab(params) { + params = Params.parse(params, { actor: this.currentGrab.actor, + isUser: false }); + + let grabStackIndex = this._findStackIndex(params.actor); + if (grabStackIndex < 0) + return; + + let focus = global.stage.key_focus; + let hadFocus = focus && this._isWithinGrabbedActor(focus); + + let poppedGrabs = this._grabStack.slice(grabStackIndex); + // "Pop" all newly ungrabbed actors off the grab stack + // by truncating the array. + this._grabStack.length = grabStackIndex; + + for (let i = poppedGrabs.length - 1; i >= 0; i--) { + let poppedGrab = poppedGrabs[i]; + + if (poppedGrab.onUngrab) + poppedGrab.onUngrab(params.isUser); + + this._releaseModalGrab(); + } + + if (hadFocus) { + let poppedGrab = poppedGrabs[0]; + if (poppedGrab.savedFocus) + poppedGrab.savedFocus.grab_key_focus(); + } + } + + onCapturedEvent(event) { + let type = event.type(); + + if (type == Clutter.EventType.KEY_PRESS && + event.get_key_symbol() == Clutter.KEY_Escape) { + this.ungrab({ isUser: true }); + return Clutter.EVENT_STOP; + } + + let motion = type == Clutter.EventType.MOTION; + let press = type == Clutter.EventType.BUTTON_PRESS; + let release = type == Clutter.EventType.BUTTON_RELEASE; + let button = press || release; + + let touchUpdate = type == Clutter.EventType.TOUCH_UPDATE; + let touchBegin = type == Clutter.EventType.TOUCH_BEGIN; + let touchEnd = type == Clutter.EventType.TOUCH_END; + let touch = touchUpdate || touchBegin || touchEnd; + + if (touch && !global.display.is_pointer_emulating_sequence(event.get_event_sequence())) + return Clutter.EVENT_PROPAGATE; + + if (this._ignoreUntilRelease && (motion || release || touch)) { + if (release || touchEnd) + this._ignoreUntilRelease = false; + return Clutter.EVENT_STOP; + } + + if (this._isWithinGrabbedActor(event.get_source())) + return Clutter.EVENT_PROPAGATE; + + if (Main.keyboard.shouldTakeEvent(event)) + return Clutter.EVENT_PROPAGATE; + + if (button || touchBegin) { + // If we have a press event, ignore the next + // motion/release events. + if (press || touchBegin) + this._ignoreUntilRelease = true; + + let i = this._actorInGrabStack(event.get_source()) + 1; + this.ungrab({ actor: this._grabStack[i].actor, isUser: true }); + return Clutter.EVENT_STOP; + } + + return Clutter.EVENT_STOP; + } +}; |