gfx/layers/apz/util/ActiveElementManager.cpp

branch
TOR_BUG_9701
changeset 15
b8a032363ba2
equal deleted inserted replaced
-1:000000000000 0:009ed37c67de
1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2 /* This Source Code Form is subject to the terms of the Mozilla Public
3 * License, v. 2.0. If a copy of the MPL was not distributed with this
4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
5
6 #include "ActiveElementManager.h"
7 #include "mozilla/EventStates.h"
8 #include "mozilla/Preferences.h"
9 #include "mozilla/Services.h"
10 #include "inIDOMUtils.h"
11 #include "nsIDOMDocument.h"
12 #include "nsIDOMElement.h"
13 #include "nsIDOMEventTarget.h"
14 #include "base/message_loop.h"
15 #include "base/task.h"
16
17 namespace mozilla {
18 namespace layers {
19
20 static int32_t sActivationDelayMs = 100;
21 static bool sActivationDelayMsSet = false;
22
23 ActiveElementManager::ActiveElementManager()
24 : mDomUtils(services::GetInDOMUtils()),
25 mCanBePan(false),
26 mCanBePanSet(false),
27 mSetActiveTask(nullptr)
28 {
29 if (!sActivationDelayMsSet) {
30 Preferences::AddIntVarCache(&sActivationDelayMs,
31 "ui.touch_activation.delay_ms",
32 sActivationDelayMs);
33 sActivationDelayMsSet = true;
34 }
35 }
36
37 ActiveElementManager::~ActiveElementManager() {}
38
39 void
40 ActiveElementManager::SetTargetElement(nsIDOMEventTarget* aTarget)
41 {
42 if (mTarget) {
43 // Multiple fingers on screen (since HandleTouchEnd clears mTarget).
44 CancelTask();
45 ResetActive();
46 mTarget = nullptr;
47 return;
48 }
49
50 mTarget = do_QueryInterface(aTarget);
51 TriggerElementActivation();
52 }
53
54 void
55 ActiveElementManager::HandleTouchStart(bool aCanBePan)
56 {
57 mCanBePan = aCanBePan;
58 mCanBePanSet = true;
59 TriggerElementActivation();
60 }
61
62 void
63 ActiveElementManager::TriggerElementActivation()
64 {
65 // Both HandleTouchStart() and SetTargetElement() call this. They can be
66 // called in either order. One will set mCanBePanSet, and the other, mTarget.
67 // We want to actually trigger the activation once both are set.
68 if (!(mTarget && mCanBePanSet)) {
69 return;
70 }
71
72 // If the touch cannot be a pan, make mTarget :active right away.
73 // Otherwise, wait a bit to see if the user will pan or not.
74 if (!mCanBePan) {
75 SetActive(mTarget);
76 } else {
77 mSetActiveTask = NewRunnableMethod(
78 this, &ActiveElementManager::SetActiveTask, mTarget);
79 MessageLoop::current()->PostDelayedTask(
80 FROM_HERE, mSetActiveTask, sActivationDelayMs);
81 }
82 }
83
84 void
85 ActiveElementManager::HandlePanStart()
86 {
87 // The user started to pan, so we don't want mTarget to be :active.
88 // Make it not :active, and clear any pending task to make it :active.
89 CancelTask();
90 ResetActive();
91 }
92
93 void
94 ActiveElementManager::HandleTouchEnd(bool aWasClick)
95 {
96 // If the touch was a click, make mTarget :active right away.
97 // nsEventStateManager will reset the active element when processing
98 // the mouse-down event generated by the click.
99 CancelTask();
100 if (aWasClick) {
101 SetActive(mTarget);
102 }
103
104 // Clear mTarget for next touch.
105 mTarget = nullptr;
106 }
107
108 void
109 ActiveElementManager::SetActive(nsIDOMElement* aTarget)
110 {
111 if (mDomUtils) {
112 mDomUtils->SetContentState(aTarget, NS_EVENT_STATE_ACTIVE.GetInternalValue());;
113 }
114 }
115
116 void
117 ActiveElementManager::ResetActive()
118 {
119 // Clear the :active flag from mTarget by setting it on the document root.
120 if (mTarget) {
121 nsCOMPtr<nsIDOMDocument> doc;
122 mTarget->GetOwnerDocument(getter_AddRefs(doc));
123 if (doc) {
124 nsCOMPtr<nsIDOMElement> root;
125 doc->GetDocumentElement(getter_AddRefs(root));
126 if (root) {
127 SetActive(root);
128 }
129 }
130 }
131 }
132
133 void
134 ActiveElementManager::SetActiveTask(nsIDOMElement* aTarget)
135 {
136 // This gets called from mSetActiveTask's Run() method. The message loop
137 // deletes the task right after running it, so we need to null out
138 // mSetActiveTask to make sure we're not left with a dangling pointer.
139 mSetActiveTask = nullptr;
140 SetActive(aTarget);
141 }
142
143 void
144 ActiveElementManager::CancelTask()
145 {
146 if (mSetActiveTask) {
147 mSetActiveTask->Cancel();
148 mSetActiveTask = nullptr;
149 }
150 }
151
152 }
153 }

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