1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
3 /* This Source Code Form is subject to the terms of the Mozilla Public
4 * License, v. 2.0. If a copy of the MPL was not distributed with this
5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
6
7 #include "VisualViewport.h"
8
9 #include "mozilla/EventDispatcher.h"
10 #include "mozilla/PresShell.h"
11 #include "mozilla/ToString.h"
12 #include "nsIScrollableFrame.h"
13 #include "nsIDocShell.h"
14 #include "nsPresContext.h"
15 #include "nsRefreshDriver.h"
16 #include "DocumentInlines.h"
17
18 static mozilla::LazyLogModule sVvpLog("visualviewport");
19 #define VVP_LOG(...) MOZ_LOG(sVvpLog, LogLevel::Debug, (__VA_ARGS__))
20
21 using namespace mozilla;
22 using namespace mozilla::dom;
23
VisualViewport(nsPIDOMWindowInner * aWindow)24 VisualViewport::VisualViewport(nsPIDOMWindowInner* aWindow)
25 : DOMEventTargetHelper(aWindow) {}
26
~VisualViewport()27 VisualViewport::~VisualViewport() {
28 if (mResizeEvent) {
29 mResizeEvent->Revoke();
30 }
31
32 if (mScrollEvent) {
33 mScrollEvent->Revoke();
34 }
35 }
36
37 /* virtual */
WrapObject(JSContext * aCx,JS::Handle<JSObject * > aGivenProto)38 JSObject* VisualViewport::WrapObject(JSContext* aCx,
39 JS::Handle<JSObject*> aGivenProto) {
40 return VisualViewport_Binding::Wrap(aCx, this, aGivenProto);
41 }
42
43 /* virtual */
GetEventTargetParent(EventChainPreVisitor & aVisitor)44 void VisualViewport::GetEventTargetParent(EventChainPreVisitor& aVisitor) {
45 EventMessage msg = aVisitor.mEvent->mMessage;
46
47 aVisitor.mCanHandle = true;
48 EventTarget* parentTarget = nullptr;
49 // Only our special internal events are allowed to escape the
50 // Visual Viewport and be dispatched further up the DOM tree.
51 if (msg == eMozVisualScroll || msg == eMozVisualResize) {
52 if (nsPIDOMWindowInner* win = GetOwner()) {
53 if (Document* doc = win->GetExtantDoc()) {
54 parentTarget = doc;
55 }
56 }
57 }
58 aVisitor.SetParentTarget(parentTarget, false);
59 }
60
VisualViewportSize() const61 CSSSize VisualViewport::VisualViewportSize() const {
62 CSSSize size = CSSSize(0, 0);
63
64 // Flush layout, as that may affect the answer below (e.g. scrollbars
65 // may have appeared, decreasing the available viewport size).
66 RefPtr<const VisualViewport> kungFuDeathGrip(this);
67 if (Document* doc = GetDocument()) {
68 doc->FlushPendingNotifications(FlushType::Layout);
69 }
70
71 // Fetch the pres shell after the layout flush, as it might have destroyed it.
72 if (PresShell* presShell = GetPresShell()) {
73 if (presShell->IsVisualViewportSizeSet()) {
74 DynamicToolbarState state = presShell->GetDynamicToolbarState();
75 size = CSSRect::FromAppUnits(
76 (state == DynamicToolbarState::InTransition ||
77 state == DynamicToolbarState::Collapsed)
78 ? presShell->GetVisualViewportSizeUpdatedByDynamicToolbar()
79 : presShell->GetVisualViewportSize());
80 } else {
81 nsIScrollableFrame* sf = presShell->GetRootScrollFrameAsScrollable();
82 if (sf) {
83 size = CSSRect::FromAppUnits(sf->GetScrollPortRect().Size());
84 }
85 }
86 }
87 return size;
88 }
89
Width() const90 double VisualViewport::Width() const {
91 CSSSize size = VisualViewportSize();
92 return size.width;
93 }
94
Height() const95 double VisualViewport::Height() const {
96 CSSSize size = VisualViewportSize();
97 return size.height;
98 }
99
Scale() const100 double VisualViewport::Scale() const {
101 double scale = 1;
102 if (PresShell* presShell = GetPresShell()) {
103 scale = presShell->GetResolution();
104 }
105 return scale;
106 }
107
VisualViewportOffset() const108 CSSPoint VisualViewport::VisualViewportOffset() const {
109 CSSPoint offset = CSSPoint(0, 0);
110
111 if (PresShell* presShell = GetPresShell()) {
112 offset = CSSPoint::FromAppUnits(presShell->GetVisualViewportOffset());
113 }
114 return offset;
115 }
116
LayoutViewportOffset() const117 CSSPoint VisualViewport::LayoutViewportOffset() const {
118 CSSPoint offset = CSSPoint(0, 0);
119
120 if (PresShell* presShell = GetPresShell()) {
121 offset = CSSPoint::FromAppUnits(presShell->GetLayoutViewportOffset());
122 }
123 return offset;
124 }
125
PageLeft() const126 double VisualViewport::PageLeft() const { return VisualViewportOffset().X(); }
127
PageTop() const128 double VisualViewport::PageTop() const { return VisualViewportOffset().Y(); }
129
OffsetLeft() const130 double VisualViewport::OffsetLeft() const {
131 return PageLeft() - LayoutViewportOffset().X();
132 }
133
OffsetTop() const134 double VisualViewport::OffsetTop() const {
135 return PageTop() - LayoutViewportOffset().Y();
136 }
137
GetDocument() const138 Document* VisualViewport::GetDocument() const {
139 nsCOMPtr<nsPIDOMWindowInner> window = GetOwner();
140 if (!window) {
141 return nullptr;
142 }
143
144 nsIDocShell* docShell = window->GetDocShell();
145 if (!docShell) {
146 return nullptr;
147 }
148
149 return docShell->GetDocument();
150 }
151
GetPresShell() const152 PresShell* VisualViewport::GetPresShell() const {
153 RefPtr<Document> document = GetDocument();
154 return document ? document->GetPresShell() : nullptr;
155 }
156
GetPresContext() const157 nsPresContext* VisualViewport::GetPresContext() const {
158 RefPtr<Document> document = GetDocument();
159 return document ? document->GetPresContext() : nullptr;
160 }
161
162 /* ================= Resize event handling ================= */
163
PostResizeEvent()164 void VisualViewport::PostResizeEvent() {
165 VVP_LOG("%p: PostResizeEvent (pre-existing: %d)\n", this, !!mResizeEvent);
166 nsPresContext* presContext = GetPresContext();
167 if (mResizeEvent && mResizeEvent->HasPresContext(presContext)) {
168 return;
169 }
170 if (mResizeEvent) {
171 // prescontext changed, so discard the old resize event and queue a new one
172 mResizeEvent->Revoke();
173 mResizeEvent = nullptr;
174 }
175
176 // The event constructor will register itself with the refresh driver.
177 if (presContext) {
178 mResizeEvent = new VisualViewportResizeEvent(this, presContext);
179 VVP_LOG("%p: PostResizeEvent, created new event\n", this);
180 }
181 }
182
VisualViewportResizeEvent(VisualViewport * aViewport,nsPresContext * aPresContext)183 VisualViewport::VisualViewportResizeEvent::VisualViewportResizeEvent(
184 VisualViewport* aViewport, nsPresContext* aPresContext)
185 : Runnable("VisualViewport::VisualViewportResizeEvent"),
186 mViewport(aViewport),
187 mPresContext(aPresContext) {
188 VVP_LOG("%p: Registering PostResize on %p %p\n", aViewport, aPresContext,
189 aPresContext->RefreshDriver());
190 aPresContext->RefreshDriver()->PostVisualViewportResizeEvent(this);
191 }
192
HasPresContext(nsPresContext * aContext) const193 bool VisualViewport::VisualViewportResizeEvent::HasPresContext(
194 nsPresContext* aContext) const {
195 return mPresContext.get() == aContext;
196 }
197
Revoke()198 void VisualViewport::VisualViewportResizeEvent::Revoke() {
199 mViewport = nullptr;
200 mPresContext = nullptr;
201 }
202
203 // TODO: Convert this to MOZ_CAN_RUN_SCRIPT (bug 1415230, bug 1535398)
204 MOZ_CAN_RUN_SCRIPT_BOUNDARY NS_IMETHODIMP
Run()205 VisualViewport::VisualViewportResizeEvent::Run() {
206 if (RefPtr<VisualViewport> viewport = mViewport) {
207 viewport->FireResizeEvent();
208 }
209 return NS_OK;
210 }
211
FireResizeEvent()212 void VisualViewport::FireResizeEvent() {
213 MOZ_ASSERT(mResizeEvent);
214 mResizeEvent->Revoke();
215 mResizeEvent = nullptr;
216
217 RefPtr<nsPresContext> presContext = GetPresContext();
218
219 VVP_LOG("%p, FireResizeEvent, fire mozvisualresize\n", this);
220 WidgetEvent mozEvent(true, eMozVisualResize);
221 mozEvent.mFlags.mOnlySystemGroupDispatch = true;
222 EventDispatcher::Dispatch(this, presContext, &mozEvent);
223
224 VVP_LOG("%p, FireResizeEvent, fire VisualViewport resize\n", this);
225 WidgetEvent event(true, eResize);
226 event.mFlags.mBubbles = false;
227 event.mFlags.mCancelable = false;
228 EventDispatcher::Dispatch(this, presContext, &event);
229 }
230
231 /* ================= Scroll event handling ================= */
232
PostScrollEvent(const nsPoint & aPrevVisualOffset,const nsPoint & aPrevLayoutOffset)233 void VisualViewport::PostScrollEvent(const nsPoint& aPrevVisualOffset,
234 const nsPoint& aPrevLayoutOffset) {
235 VVP_LOG("%p: PostScrollEvent, prevRelativeOffset=%s (pre-existing: %d)\n",
236 this, ToString(aPrevVisualOffset - aPrevLayoutOffset).c_str(),
237 !!mScrollEvent);
238 nsPresContext* presContext = GetPresContext();
239 if (mScrollEvent && mScrollEvent->HasPresContext(presContext)) {
240 return;
241 }
242
243 if (mScrollEvent) {
244 // prescontext changed, so discard the old scroll event and queue a new one
245 mScrollEvent->Revoke();
246 mScrollEvent = nullptr;
247 }
248
249 // The event constructor will register itself with the refresh driver.
250 if (presContext) {
251 mScrollEvent = new VisualViewportScrollEvent(
252 this, presContext, aPrevVisualOffset, aPrevLayoutOffset);
253 VVP_LOG("%p: PostScrollEvent, created new event\n", this);
254 }
255 }
256
VisualViewportScrollEvent(VisualViewport * aViewport,nsPresContext * aPresContext,const nsPoint & aPrevVisualOffset,const nsPoint & aPrevLayoutOffset)257 VisualViewport::VisualViewportScrollEvent::VisualViewportScrollEvent(
258 VisualViewport* aViewport, nsPresContext* aPresContext,
259 const nsPoint& aPrevVisualOffset, const nsPoint& aPrevLayoutOffset)
260 : Runnable("VisualViewport::VisualViewportScrollEvent"),
261 mViewport(aViewport),
262 mPresContext(aPresContext),
263 mPrevVisualOffset(aPrevVisualOffset),
264 mPrevLayoutOffset(aPrevLayoutOffset) {
265 VVP_LOG("%p: Registering PostScroll on %p %p\n", aViewport, aPresContext,
266 aPresContext->RefreshDriver());
267 aPresContext->RefreshDriver()->PostVisualViewportScrollEvent(this);
268 }
269
HasPresContext(nsPresContext * aContext) const270 bool VisualViewport::VisualViewportScrollEvent::HasPresContext(
271 nsPresContext* aContext) const {
272 return mPresContext.get() == aContext;
273 }
274
Revoke()275 void VisualViewport::VisualViewportScrollEvent::Revoke() {
276 mViewport = nullptr;
277 mPresContext = nullptr;
278 }
279
280 // TODO: Convert this to MOZ_CAN_RUN_SCRIPT (bug 1415230, bug 1535398)
281 MOZ_CAN_RUN_SCRIPT_BOUNDARY NS_IMETHODIMP
Run()282 VisualViewport::VisualViewportScrollEvent::Run() {
283 if (RefPtr<VisualViewport> viewport = mViewport) {
284 viewport->FireScrollEvent();
285 }
286 return NS_OK;
287 }
288
FireScrollEvent()289 void VisualViewport::FireScrollEvent() {
290 MOZ_ASSERT(mScrollEvent);
291 nsPoint prevVisualOffset = mScrollEvent->PrevVisualOffset();
292 nsPoint prevLayoutOffset = mScrollEvent->PrevLayoutOffset();
293 mScrollEvent->Revoke();
294 mScrollEvent = nullptr;
295
296 if (RefPtr<PresShell> presShell = GetPresShell()) {
297 RefPtr<nsPresContext> presContext = GetPresContext();
298
299 if (presShell->GetVisualViewportOffset() != prevVisualOffset) {
300 // The internal event will be fired whenever the visual viewport's
301 // *absolute* offset changed, i.e. relative to the page.
302 VVP_LOG("%p: FireScrollEvent, fire mozvisualscroll\n", this);
303 WidgetEvent mozEvent(true, eMozVisualScroll);
304 mozEvent.mFlags.mOnlySystemGroupDispatch = true;
305 EventDispatcher::Dispatch(this, presContext, &mozEvent);
306 }
307
308 // Check whether the relative visual viewport offset actually changed -
309 // maybe both visual and layout viewport scrolled together and there was no
310 // change after all.
311 nsPoint curRelativeOffset =
312 presShell->GetVisualViewportOffsetRelativeToLayoutViewport();
313 nsPoint prevRelativeOffset = prevVisualOffset - prevLayoutOffset;
314 VVP_LOG(
315 "%p: FireScrollEvent, curRelativeOffset %s, "
316 "prevRelativeOffset %s\n",
317 this, ToString(curRelativeOffset).c_str(),
318 ToString(prevRelativeOffset).c_str());
319 if (curRelativeOffset != prevRelativeOffset) {
320 VVP_LOG("%p, FireScrollEvent, fire VisualViewport scroll\n", this);
321 WidgetGUIEvent event(true, eScroll, nullptr);
322 event.mFlags.mBubbles = false;
323 event.mFlags.mCancelable = false;
324 EventDispatcher::Dispatch(this, presContext, &event);
325 }
326 }
327 }
328