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diff --git a/layout/base/MobileViewportManager.cpp b/layout/base/MobileViewportManager.cpp
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "MobileViewportManager.h"
+
+#include "mozilla/PresShell.h"
+#include "mozilla/ToString.h"
+#include "mozilla/dom/Document.h"
+#include "mozilla/dom/Event.h"
+#include "mozilla/dom/EventTarget.h"
+#include "nsIFrame.h"
+#include "nsLayoutUtils.h"
+#include "nsViewManager.h"
+#include "nsViewportInfo.h"
+#include "UnitTransforms.h"
+
+mozilla::LazyLogModule MobileViewportManager::gLog("apz.mobileviewport");
+#define MVM_LOG(...) \
+ MOZ_LOG(MobileViewportManager::gLog, LogLevel::Debug, (__VA_ARGS__))
+
+NS_IMPL_ISUPPORTS(MobileViewportManager, nsIDOMEventListener, nsIObserver)
+
+#define DOM_META_ADDED u"DOMMetaAdded"_ns
+#define DOM_META_CHANGED u"DOMMetaChanged"_ns
+#define FULLSCREEN_CHANGED u"fullscreenchange"_ns
+#define LOAD u"load"_ns
+#define BEFORE_FIRST_PAINT "before-first-paint"_ns
+
+using namespace mozilla;
+using namespace mozilla::dom;
+using namespace mozilla::layers;
+
+MobileViewportManager::MobileViewportManager(MVMContext* aContext,
+ ManagerType aType)
+ : mContext(aContext),
+ mManagerType(aType),
+ mIsFirstPaint(false),
+ mPainted(false) {
+ MOZ_ASSERT(mContext);
+
+ MVM_LOG("%p: creating with context %p\n", this, mContext.get());
+
+ mContext->AddEventListener(DOM_META_ADDED, this, false);
+ mContext->AddEventListener(DOM_META_CHANGED, this, false);
+ mContext->AddEventListener(FULLSCREEN_CHANGED, this, false);
+ mContext->AddEventListener(LOAD, this, true);
+
+ mContext->AddObserver(this, BEFORE_FIRST_PAINT.Data(), false);
+
+ // We need to initialize the display size and the CSS viewport size before
+ // the initial reflow happens.
+ UpdateSizesBeforeReflow();
+}
+
+MobileViewportManager::~MobileViewportManager() = default;
+
+void MobileViewportManager::Destroy() {
+ MVM_LOG("%p: destroying\n", this);
+
+ mContext->RemoveEventListener(DOM_META_ADDED, this, false);
+ mContext->RemoveEventListener(DOM_META_CHANGED, this, false);
+ mContext->RemoveEventListener(FULLSCREEN_CHANGED, this, false);
+ mContext->RemoveEventListener(LOAD, this, true);
+
+ mContext->RemoveObserver(this, BEFORE_FIRST_PAINT.Data());
+
+ mContext->Destroy();
+ mContext = nullptr;
+}
+
+void MobileViewportManager::SetRestoreResolution(
+ float aResolution, LayoutDeviceIntSize aDisplaySize) {
+ SetRestoreResolution(aResolution);
+ ScreenIntSize restoreDisplaySize = ViewAs<ScreenPixel>(
+ aDisplaySize, PixelCastJustification::LayoutDeviceIsScreenForBounds);
+ mRestoreDisplaySize = Some(restoreDisplaySize);
+}
+
+void MobileViewportManager::SetRestoreResolution(float aResolution) {
+ mRestoreResolution = Some(aResolution);
+}
+
+float MobileViewportManager::ComputeIntrinsicResolution() const {
+ if (!mContext) {
+ return 1.f;
+ }
+
+ ScreenIntSize displaySize = ViewAs<ScreenPixel>(
+ mDisplaySize, PixelCastJustification::LayoutDeviceIsScreenForBounds);
+ CSSToScreenScale intrinsicScale = ComputeIntrinsicScale(
+ mContext->GetViewportInfo(displaySize), displaySize, mMobileViewportSize);
+ CSSToLayoutDeviceScale cssToDev = mContext->CSSToDevPixelScale();
+ return (intrinsicScale / cssToDev).scale;
+}
+
+mozilla::CSSToScreenScale MobileViewportManager::ComputeIntrinsicScale(
+ const nsViewportInfo& aViewportInfo,
+ const mozilla::ScreenIntSize& aDisplaySize,
+ const mozilla::CSSSize& aViewportOrContentSize) const {
+ CSSToScreenScale intrinsicScale =
+ aViewportOrContentSize.IsEmpty()
+ ? CSSToScreenScale(1.0)
+ : MaxScaleRatio(ScreenSize(aDisplaySize), aViewportOrContentSize);
+ MVM_LOG("%p: Intrinsic computed zoom is %f\n", this, intrinsicScale.scale);
+ return ClampZoom(intrinsicScale, aViewportInfo);
+}
+
+void MobileViewportManager::RequestReflow(bool aForceAdjustResolution) {
+ MVM_LOG("%p: got a reflow request with force resolution: %d\n", this,
+ aForceAdjustResolution);
+ RefreshViewportSize(aForceAdjustResolution);
+}
+
+void MobileViewportManager::ResolutionUpdated(
+ mozilla::ResolutionChangeOrigin aOrigin) {
+ MVM_LOG("%p: resolution updated\n", this);
+
+ if (!mContext) {
+ return;
+ }
+
+ if ((!mPainted &&
+ aOrigin == mozilla::ResolutionChangeOrigin::MainThreadRestore) ||
+ aOrigin == mozilla::ResolutionChangeOrigin::Test) {
+ // Save the value, so our default zoom calculation
+ // can take it into account later on.
+ SetRestoreResolution(mContext->GetResolution());
+ }
+ RefreshVisualViewportSize();
+}
+
+NS_IMETHODIMP
+MobileViewportManager::HandleEvent(dom::Event* event) {
+ nsAutoString type;
+ event->GetType(type);
+
+ if (type.Equals(DOM_META_ADDED)) {
+ HandleDOMMetaAdded();
+ } else if (type.Equals(DOM_META_CHANGED)) {
+ MVM_LOG("%p: got a dom-meta-changed event\n", this);
+ RefreshViewportSize(mPainted);
+ } else if (type.Equals(FULLSCREEN_CHANGED)) {
+ MVM_LOG("%p: got a fullscreenchange event\n", this);
+ RefreshViewportSize(mPainted);
+ } else if (type.Equals(LOAD)) {
+ MVM_LOG("%p: got a load event\n", this);
+ if (!mPainted) {
+ // Load event got fired before the before-first-paint message
+ SetInitialViewport();
+ }
+ }
+ return NS_OK;
+}
+
+void MobileViewportManager::HandleDOMMetaAdded() {
+ MVM_LOG("%p: got a dom-meta-added event\n", this);
+ if (mPainted && mContext->IsDocumentLoading()) {
+ // It's possible that we get a DOMMetaAdded event after the page
+ // has already been painted, but before the document finishes loading.
+ // In such a case, we've already run SetInitialViewport() on
+ // "before-first-paint", and won't run it again on "load" (because
+ // mPainted=true). But that SetInitialViewport() call didn't know the
+ // "initial-scale" from this meta viewport tag. To ensure we respect
+ // the "initial-scale", call SetInitialViewport() again.
+ // Note: It's important that we only do this if mPainted=true. In the
+ // usual case, we get the DOMMetaAdded before the first paint, sometimes
+ // even before we have a frame tree, and calling SetInitialViewport()
+ // before we have a frame tree will skip some important steps (e.g.
+ // updating display port margins).
+ SetInitialViewport();
+ } else {
+ RefreshViewportSize(mPainted);
+ }
+}
+
+NS_IMETHODIMP
+MobileViewportManager::Observe(nsISupports* aSubject, const char* aTopic,
+ const char16_t* aData) {
+ if (!mContext) {
+ return NS_OK;
+ }
+
+ if (mContext->SubjectMatchesDocument(aSubject) &&
+ BEFORE_FIRST_PAINT.EqualsASCII(aTopic)) {
+ MVM_LOG("%p: got a before-first-paint event\n", this);
+ if (!mPainted) {
+ // before-first-paint message arrived before load event
+ SetInitialViewport();
+ }
+ }
+ return NS_OK;
+}
+
+void MobileViewportManager::SetInitialViewport() {
+ MVM_LOG("%p: setting initial viewport\n", this);
+ mIsFirstPaint = true;
+ mPainted = true;
+ RefreshViewportSize(false);
+}
+
+CSSToScreenScale MobileViewportManager::ClampZoom(
+ const CSSToScreenScale& aZoom, const nsViewportInfo& aViewportInfo) const {
+ CSSToScreenScale zoom = aZoom;
+ if (std::isnan(zoom.scale)) {
+ NS_ERROR("Don't pass NaN to ClampZoom; check caller for 0/0 division");
+ zoom = CSSToScreenScale(1.0);
+ }
+
+ if (zoom < aViewportInfo.GetMinZoom()) {
+ zoom = aViewportInfo.GetMinZoom();
+ MVM_LOG("%p: Clamped to %f\n", this, zoom.scale);
+ }
+ if (zoom > aViewportInfo.GetMaxZoom()) {
+ zoom = aViewportInfo.GetMaxZoom();
+ MVM_LOG("%p: Clamped to %f\n", this, zoom.scale);
+ }
+
+ // Non-positive zoom factors can produce NaN or negative viewport sizes,
+ // so we better be sure we've got a positive zoom factor. Just for good
+ // measure, we check our min/max as well as the final clamped value.
+ MOZ_ASSERT(aViewportInfo.GetMinZoom() > CSSToScreenScale(0.0f),
+ "zoom factor must be positive");
+ MOZ_ASSERT(aViewportInfo.GetMaxZoom() > CSSToScreenScale(0.0f),
+ "zoom factor must be positive");
+ MOZ_ASSERT(zoom > CSSToScreenScale(0.0f), "zoom factor must be positive");
+ return zoom;
+}
+
+CSSToScreenScale MobileViewportManager::ScaleZoomWithDisplayWidth(
+ const CSSToScreenScale& aZoom, const float& aDisplayWidthChangeRatio,
+ const CSSSize& aNewViewport, const CSSSize& aOldViewport) {
+ float inverseCssWidthChangeRatio =
+ (aNewViewport.width == 0) ? 1.0f
+ : aOldViewport.width / aNewViewport.width;
+ CSSToScreenScale newZoom(aZoom.scale * aDisplayWidthChangeRatio *
+ inverseCssWidthChangeRatio);
+ MVM_LOG("%p: Old zoom was %f, changed by %f * %f to %f\n", this, aZoom.scale,
+ aDisplayWidthChangeRatio, inverseCssWidthChangeRatio, newZoom.scale);
+ return newZoom;
+}
+
+CSSToScreenScale MobileViewportManager::ResolutionToZoom(
+ const LayoutDeviceToLayerScale& aResolution) const {
+ return ViewTargetAs<ScreenPixel>(
+ mContext->CSSToDevPixelScale() * aResolution / ParentLayerToLayerScale(1),
+ PixelCastJustification::ScreenIsParentLayerForRoot);
+}
+
+LayoutDeviceToLayerScale MobileViewportManager::ZoomToResolution(
+ const CSSToScreenScale& aZoom) const {
+ return ViewTargetAs<ParentLayerPixel>(
+ aZoom, PixelCastJustification::ScreenIsParentLayerForRoot) /
+ mContext->CSSToDevPixelScale() * ParentLayerToLayerScale(1);
+}
+
+void MobileViewportManager::UpdateResolutionForFirstPaint(
+ const CSSSize& aViewportSize) {
+ ScreenIntSize displaySize = ViewAs<ScreenPixel>(
+ mDisplaySize, PixelCastJustification::LayoutDeviceIsScreenForBounds);
+ nsViewportInfo viewportInfo = mContext->GetViewportInfo(displaySize);
+ ScreenIntSize compositionSize = GetCompositionSize(displaySize);
+
+ if (mRestoreResolution) {
+ LayoutDeviceToLayerScale restoreResolution(*mRestoreResolution);
+ CSSToScreenScale restoreZoom = ResolutionToZoom(restoreResolution);
+ if (mRestoreDisplaySize) {
+ CSSSize prevViewport =
+ mContext->GetViewportInfo(*mRestoreDisplaySize).GetSize();
+ float restoreDisplayWidthChangeRatio =
+ (mRestoreDisplaySize->width > 0)
+ ? (float)compositionSize.width / (float)mRestoreDisplaySize->width
+ : 1.0f;
+
+ restoreZoom =
+ ScaleZoomWithDisplayWidth(restoreZoom, restoreDisplayWidthChangeRatio,
+ aViewportSize, prevViewport);
+ }
+ MVM_LOG("%p: restored zoom is %f\n", this, restoreZoom.scale);
+ restoreZoom = ClampZoom(restoreZoom, viewportInfo);
+
+ ApplyNewZoom(displaySize, restoreZoom);
+ return;
+ }
+
+ CSSToScreenScale defaultZoom = viewportInfo.GetDefaultZoom();
+ MVM_LOG("%p: default zoom from viewport is %f\n", this, defaultZoom.scale);
+ if (!viewportInfo.IsDefaultZoomValid()) {
+ CSSSize contentSize = aViewportSize;
+ if (Maybe<CSSRect> scrollableRect =
+ mContext->CalculateScrollableRectForRSF()) {
+ contentSize = scrollableRect->Size();
+ }
+ defaultZoom =
+ ComputeIntrinsicScale(viewportInfo, compositionSize, contentSize);
+ }
+ MOZ_ASSERT(viewportInfo.GetMinZoom() <= defaultZoom &&
+ defaultZoom <= viewportInfo.GetMaxZoom());
+
+ ApplyNewZoom(displaySize, defaultZoom);
+}
+
+void MobileViewportManager::UpdateResolutionForViewportSizeChange(
+ const CSSSize& aViewportSize,
+ const Maybe<float>& aDisplayWidthChangeRatio) {
+ ScreenIntSize displaySize = ViewAs<ScreenPixel>(
+ mDisplaySize, PixelCastJustification::LayoutDeviceIsScreenForBounds);
+ nsViewportInfo viewportInfo = mContext->GetViewportInfo(displaySize);
+
+ CSSToScreenScale zoom = GetZoom();
+ // Non-positive zoom factors can produce NaN or negative viewport sizes,
+ // so we better be sure we've got a positive zoom factor.
+ MOZ_ASSERT(zoom > CSSToScreenScale(0.0f), "zoom factor must be positive");
+
+ MOZ_ASSERT(!mIsFirstPaint);
+
+ // If this is not a first paint, then in some cases we want to update the
+ // pre- existing resolution so as to maintain how much actual content is
+ // visible within the display width. Note that "actual content" may be
+ // different with respect to CSS pixels because of the CSS viewport size
+ // changing.
+ //
+ // aDisplayWidthChangeRatio is non-empty if:
+ // (a) The meta-viewport tag information changes, and so the CSS viewport
+ // might change as a result. If this happens after the content has
+ // been painted, we want to adjust the zoom to compensate. OR
+ // (b) The display size changed from a nonzero value to another
+ // nonzero value. This covers the case where e.g. the device was
+ // rotated, and again we want to adjust the zoom to compensate.
+ // Note in particular that aDisplayWidthChangeRatio will be None if all
+ // that happened was a change in the full-zoom. In this case, we still
+ // want to compute a new CSS and visual viewport, but we don't want to update
+ // the resolution.
+ //
+ // Given the above, the algorithm below accounts for all types of changes
+ // I can conceive of:
+ // 1. screen size changes, CSS viewport does not (pages with no meta
+ // viewport or a fixed size viewport)
+ // 2. screen size changes, CSS viewport also does (pages with a
+ // device-width viewport)
+ // 3. screen size remains constant, but CSS viewport changes (meta
+ // viewport tag is added or removed)
+ // 4. neither screen size nor CSS viewport changes
+
+ if (!aDisplayWidthChangeRatio) {
+ UpdateVisualViewportSize(displaySize, zoom);
+ return;
+ }
+
+ // One more complication is that our current zoom level may be the
+ // result of clamping to either the minimum or maximum zoom level
+ // allowed by the viewport. If we naively scale the zoom level with
+ // the change in the display width, we might be scaling one of these
+ // previously clamped values. What we really want to do is to make
+ // scaling of the zoom aware of these minimum and maximum clamping
+ // points for the existing content size, so that we keep display
+ // width changes completely reversible.
+
+ // We don't consider here if we are scaling to a zoom value outside
+ // of our viewport limits, because we'll clamp to the viewport limits
+ // as a final step.
+
+ // Because of the behavior of ShrinkToDisplaySizeIfNeeded, we are
+ // choosing zoom clamping points based on the content size of the
+ // scrollable rect, which might different from aViewportSize.
+ CSSSize contentSize = aViewportSize;
+ if (Maybe<CSSRect> scrollableRect =
+ mContext->CalculateScrollableRectForRSF()) {
+ contentSize = scrollableRect->Size();
+ }
+
+ // We scale the sizes, though we only care about the scaled widths.
+ ScreenSize minZoomDisplaySize = contentSize * viewportInfo.GetMinZoom();
+ ScreenSize maxZoomDisplaySize = contentSize * viewportInfo.GetMaxZoom();
+
+ ScreenSize newDisplaySize(displaySize);
+ ScreenSize oldDisplaySize = newDisplaySize / *aDisplayWidthChangeRatio;
+
+ // To calculate an adjusted ratio, we use some combination of these
+ // four values:
+ float a(minZoomDisplaySize.width);
+ float b(maxZoomDisplaySize.width);
+ float c(oldDisplaySize.width);
+ float d(newDisplaySize.width);
+
+ // The oldDisplaySize value is in one of three "zones":
+ // 1) Less than or equal to minZoomDisplaySize.
+ // 2) Between minZoomDisplaySize and maxZoomDisplaySize.
+ // 3) Greater than or equal to maxZoomDisplaySize.
+
+ // Depending on which zone each are in, the adjusted ratio is shown in
+ // the table below (using the a-b-c-d coding from above):
+
+ // c +---+
+ // | d |
+ // 1 | a |
+ // +---+
+ // | d |
+ // 2 | c |
+ // +---+
+ // | d |
+ // 3 | b |
+ // +---+
+
+ // Conveniently, the denominator is c clamped to a..b.
+ float denominator = clamped(c, a, b);
+
+ float adjustedRatio = d / denominator;
+ CSSToScreenScale adjustedZoom = ScaleZoomWithDisplayWidth(
+ zoom, adjustedRatio, aViewportSize, mMobileViewportSize);
+ CSSToScreenScale newZoom = ClampZoom(adjustedZoom, viewportInfo);
+
+ ApplyNewZoom(displaySize, newZoom);
+}
+
+void MobileViewportManager::UpdateResolutionForContentSizeChange(
+ const CSSSize& aContentSize) {
+ ScreenIntSize displaySize = ViewAs<ScreenPixel>(
+ mDisplaySize, PixelCastJustification::LayoutDeviceIsScreenForBounds);
+ nsViewportInfo viewportInfo = mContext->GetViewportInfo(displaySize);
+
+ CSSToScreenScale zoom = GetZoom();
+ // Non-positive zoom factors can produce NaN or negative viewport sizes,
+ // so we better be sure we've got a positive zoom factor.
+ MOZ_ASSERT(zoom > CSSToScreenScale(0.0f), "zoom factor must be positive");
+
+ ScreenIntSize compositionSize = GetCompositionSize(displaySize);
+ CSSToScreenScale intrinsicScale =
+ ComputeIntrinsicScale(viewportInfo, compositionSize, aContentSize);
+
+ // We try to scale down the contents only IF the document has no
+ // initial-scale AND IF it's not restored documents AND IF the resolution
+ // has never been changed by APZ.
+ if (MOZ_LOG_TEST(gLog, LogLevel::Debug)) {
+ MVM_LOG("%p: conditions preventing shrink-to-fit: %d %d %d\n", this,
+ mRestoreResolution.isSome(), mContext->IsResolutionUpdatedByApz(),
+ viewportInfo.IsDefaultZoomValid());
+ }
+ if (!mRestoreResolution && !mContext->IsResolutionUpdatedByApz() &&
+ !viewportInfo.IsDefaultZoomValid()) {
+ if (zoom != intrinsicScale) {
+ ApplyNewZoom(displaySize, intrinsicScale);
+ }
+ return;
+ }
+
+ // Even in other scenarios, we want to ensure that zoom level is
+ // not _smaller_ than the intrinsic scale, otherwise we might be
+ // trying to show regions where there is no content to show.
+ CSSToScreenScale clampedZoom = zoom;
+
+ if (clampedZoom < intrinsicScale) {
+ clampedZoom = intrinsicScale;
+ }
+
+ // Also clamp to the restrictions imposed by viewportInfo.
+ clampedZoom = ClampZoom(clampedZoom, viewportInfo);
+
+ if (clampedZoom != zoom) {
+ ApplyNewZoom(displaySize, clampedZoom);
+ }
+}
+
+void MobileViewportManager::ApplyNewZoom(const ScreenIntSize& aDisplaySize,
+ const CSSToScreenScale& aNewZoom) {
+ // If the zoom has changed, update the pres shell resolution accordingly.
+ // We characterize this as MainThreadAdjustment, because we don't want our
+ // change here to be remembered as a restore resolution.
+
+ // Non-positive zoom factors can produce NaN or negative viewport sizes,
+ // so we better be sure we've got a positive zoom factor.
+ MOZ_ASSERT(aNewZoom > CSSToScreenScale(0.0f), "zoom factor must be positive");
+
+ LayoutDeviceToLayerScale resolution = ZoomToResolution(aNewZoom);
+ MVM_LOG("%p: setting resolution %f\n", this, resolution.scale);
+ mContext->SetResolutionAndScaleTo(
+ resolution.scale, ResolutionChangeOrigin::MainThreadAdjustment);
+
+ MVM_LOG("%p: New zoom is %f\n", this, aNewZoom.scale);
+
+ UpdateVisualViewportSize(aDisplaySize, aNewZoom);
+}
+
+ScreenIntSize MobileViewportManager::GetCompositionSize(
+ const ScreenIntSize& aDisplaySize) const {
+ if (!mContext) {
+ return ScreenIntSize();
+ }
+
+ // FIXME: Bug 1586986 - To update VisualViewport in response to the dynamic
+ // toolbar transition we probably need to include the dynamic toolbar
+ // _current_ height.
+ ScreenIntSize compositionSize(aDisplaySize);
+ ScreenMargin scrollbars =
+ mContext->ScrollbarAreaToExcludeFromCompositionBounds()
+ // Scrollbars are not subject to resolution scaling, so LD pixels =
+ // Screen pixels for them.
+ * LayoutDeviceToScreenScale(1.0f);
+
+ compositionSize.width =
+ std::max(0.0f, compositionSize.width - scrollbars.LeftRight());
+ compositionSize.height =
+ std::max(0.0f, compositionSize.height - scrollbars.TopBottom());
+
+ return compositionSize;
+}
+
+void MobileViewportManager::UpdateVisualViewportSize(
+ const ScreenIntSize& aDisplaySize, const CSSToScreenScale& aZoom) {
+ if (!mContext) {
+ return;
+ }
+
+ ScreenSize compositionSize = ScreenSize(GetCompositionSize(aDisplaySize));
+
+ CSSSize compSize = compositionSize / aZoom;
+ MVM_LOG("%p: Setting VVPS %s\n", this, ToString(compSize).c_str());
+ mContext->SetVisualViewportSize(compSize);
+}
+
+CSSToScreenScale MobileViewportManager::GetZoom() const {
+ LayoutDeviceToLayerScale res(mContext->GetResolution());
+ return ResolutionToZoom(res);
+}
+
+void MobileViewportManager::UpdateVisualViewportSizeByDynamicToolbar(
+ ScreenIntCoord aToolbarHeight) {
+ if (!mContext) {
+ return;
+ }
+
+ ScreenIntSize displaySize = ViewAs<ScreenPixel>(
+ mDisplaySize, PixelCastJustification::LayoutDeviceIsScreenForBounds);
+ displaySize.height += aToolbarHeight;
+ CSSSize compSize = ScreenSize(GetCompositionSize(displaySize)) / GetZoom();
+
+ mVisualViewportSizeUpdatedByDynamicToolbar =
+ nsSize(nsPresContext::CSSPixelsToAppUnits(compSize.width),
+ nsPresContext::CSSPixelsToAppUnits(compSize.height));
+
+ mContext->PostVisualViewportResizeEventByDynamicToolbar();
+}
+
+void MobileViewportManager::
+ UpdateVisualViewportSizeForPotentialScrollbarChange() {
+ RefreshVisualViewportSize();
+}
+
+void MobileViewportManager::UpdateDisplayPortMargins() {
+ if (!mContext) {
+ return;
+ }
+ mContext->UpdateDisplayPortMargins();
+}
+
+void MobileViewportManager::RefreshVisualViewportSize() {
+ // This function is a subset of RefreshViewportSize, and only updates the
+ // visual viewport size.
+
+ if (!mContext) {
+ return;
+ }
+
+ ScreenIntSize displaySize = ViewAs<ScreenPixel>(
+ mDisplaySize, PixelCastJustification::LayoutDeviceIsScreenForBounds);
+
+ if (displaySize.width == 0 || displaySize.height == 0) {
+ return;
+ }
+
+ UpdateVisualViewportSize(displaySize, GetZoom());
+}
+
+void MobileViewportManager::UpdateSizesBeforeReflow() {
+ if (Maybe<LayoutDeviceIntSize> newDisplaySize =
+ mContext->GetContentViewerSize()) {
+ mDisplaySize = *newDisplaySize;
+ MVM_LOG("%p: Reflow starting, display size updated to %s\n", this,
+ ToString(mDisplaySize).c_str());
+
+ if (mDisplaySize.width == 0 || mDisplaySize.height == 0) {
+ return;
+ }
+
+ ScreenIntSize displaySize = ViewAs<ScreenPixel>(
+ mDisplaySize, PixelCastJustification::LayoutDeviceIsScreenForBounds);
+ nsViewportInfo viewportInfo = mContext->GetViewportInfo(displaySize);
+ mMobileViewportSize = viewportInfo.GetSize();
+ MVM_LOG("%p: MVSize updated to %s\n", this,
+ ToString(mMobileViewportSize).c_str());
+ }
+}
+
+void MobileViewportManager::RefreshViewportSize(bool aForceAdjustResolution) {
+ // This function gets called by the various triggers that may result in a
+ // change of the CSS viewport. In some of these cases (e.g. the meta-viewport
+ // tag changes) we want to update the resolution and in others (e.g. the full
+ // zoom changing) we don't want to update the resolution. See the comment in
+ // UpdateResolutionForViewportSizeChange for some more detail on this.
+ // An important assumption we
+ // make here is that this RefreshViewportSize function will be called
+ // separately for each trigger that changes. For instance it should never get
+ // called such that both the full zoom and the meta-viewport tag have changed;
+ // instead it would get called twice - once after each trigger changes. This
+ // assumption is what allows the aForceAdjustResolution parameter to work as
+ // intended; if this assumption is violated then we will need to add extra
+ // complicated logic in UpdateResolutionForViewportSizeChange to ensure we
+ // only do the resolution update in the right scenarios.
+
+ if (!mContext) {
+ return;
+ }
+
+ Maybe<float> displayWidthChangeRatio;
+ if (Maybe<LayoutDeviceIntSize> newDisplaySize =
+ mContext->GetContentViewerSize()) {
+ // See the comment in UpdateResolutionForViewportSizeChange for why we're
+ // doing this.
+ if (mDisplaySize.width > 0) {
+ if (aForceAdjustResolution ||
+ mDisplaySize.width != newDisplaySize->width) {
+ displayWidthChangeRatio =
+ Some((float)newDisplaySize->width / (float)mDisplaySize.width);
+ }
+ } else if (aForceAdjustResolution) {
+ displayWidthChangeRatio = Some(1.0f);
+ }
+
+ MVM_LOG("%p: Display width change ratio is %f\n", this,
+ displayWidthChangeRatio.valueOr(0.0f));
+ mDisplaySize = *newDisplaySize;
+ }
+
+ MVM_LOG("%p: Computing CSS viewport using %d,%d\n", this, mDisplaySize.width,
+ mDisplaySize.height);
+ if (mDisplaySize.width == 0 || mDisplaySize.height == 0) {
+ // We can't do anything useful here, we should just bail out
+ return;
+ }
+
+ ScreenIntSize displaySize = ViewAs<ScreenPixel>(
+ mDisplaySize, PixelCastJustification::LayoutDeviceIsScreenForBounds);
+ nsViewportInfo viewportInfo = mContext->GetViewportInfo(displaySize);
+ MVM_LOG("%p: viewport info has zooms min=%f max=%f default=%f,valid=%d\n",
+ this, viewportInfo.GetMinZoom().scale,
+ viewportInfo.GetMaxZoom().scale, viewportInfo.GetDefaultZoom().scale,
+ viewportInfo.IsDefaultZoomValid());
+
+ CSSSize viewport = viewportInfo.GetSize();
+ MVM_LOG("%p: Computed CSS viewport %s\n", this, ToString(viewport).c_str());
+
+ if (!mIsFirstPaint && mMobileViewportSize == viewport) {
+ // Nothing changed, so no need to do a reflow
+ return;
+ }
+
+ // If it's the first-paint or the viewport changed, we need to update
+ // various APZ properties (the zoom and some things that might depend on it)
+ MVM_LOG("%p: Updating properties because %d || %d\n", this, mIsFirstPaint,
+ mMobileViewportSize != viewport);
+
+ if (mManagerType == ManagerType::VisualAndMetaViewport &&
+ (aForceAdjustResolution || mContext->AllowZoomingForDocument())) {
+ MVM_LOG("%p: Updating resolution because %d || %d\n", this,
+ aForceAdjustResolution, mContext->AllowZoomingForDocument());
+ if (mIsFirstPaint) {
+ UpdateResolutionForFirstPaint(viewport);
+ } else {
+ UpdateResolutionForViewportSizeChange(viewport, displayWidthChangeRatio);
+ }
+ } else {
+ // Even without zoom, we need to update that the visual viewport size
+ // has changed.
+ MVM_LOG("%p: Updating VV size\n", this);
+ RefreshVisualViewportSize();
+ }
+ if (gfxPlatform::AsyncPanZoomEnabled()) {
+ UpdateDisplayPortMargins();
+ }
+
+ // Update internal state.
+ mMobileViewportSize = viewport;
+
+ if (mManagerType == ManagerType::VisualViewportOnly) {
+ MVM_LOG("%p: Visual-only, so aborting before reflow\n", this);
+ mIsFirstPaint = false;
+ return;
+ }
+
+ RefPtr<MobileViewportManager> strongThis(this);
+
+ // Kick off a reflow.
+ MVM_LOG("%p: Triggering reflow with viewport %s\n", this,
+ ToString(viewport).c_str());
+ mContext->Reflow(viewport);
+
+ // We are going to fit the content to the display width if the initial-scale
+ // is not specied and if the content is still wider than the display width.
+ ShrinkToDisplaySizeIfNeeded();
+
+ mIsFirstPaint = false;
+}
+
+void MobileViewportManager::ShrinkToDisplaySizeIfNeeded() {
+ if (!mContext) {
+ return;
+ }
+
+ if (mManagerType == ManagerType::VisualViewportOnly) {
+ MVM_LOG("%p: Visual-only, so aborting ShrinkToDisplaySizeIfNeeded\n", this);
+ return;
+ }
+
+ if (!mContext->AllowZoomingForDocument() || mContext->IsInReaderMode()) {
+ // If zoom is disabled, we don't scale down wider contents to fit them
+ // into device screen because users won't be able to zoom out the tiny
+ // contents.
+ // We special-case reader mode, because it doesn't allow zooming, but
+ // the restriction is often not yet in place at the time this logic
+ // runs.
+ return;
+ }
+
+ if (Maybe<CSSRect> scrollableRect =
+ mContext->CalculateScrollableRectForRSF()) {
+ MVM_LOG("%p: ShrinkToDisplaySize using scrollableRect %s\n", this,
+ ToString(scrollableRect->Size()).c_str());
+ UpdateResolutionForContentSizeChange(scrollableRect->Size());
+ }
+}
+
+CSSSize MobileViewportManager::GetIntrinsicCompositionSize() const {
+ ScreenIntSize displaySize = ViewAs<ScreenPixel>(
+ mDisplaySize, PixelCastJustification::LayoutDeviceIsScreenForBounds);
+ ScreenIntSize compositionSize = GetCompositionSize(displaySize);
+ CSSToScreenScale intrinsicScale =
+ ComputeIntrinsicScale(mContext->GetViewportInfo(displaySize),
+ compositionSize, mMobileViewportSize);
+
+ return ScreenSize(compositionSize) / intrinsicScale;
+}
+
+ParentLayerSize MobileViewportManager::GetCompositionSizeWithoutDynamicToolbar()
+ const {
+ ScreenIntSize displaySize = ViewAs<ScreenPixel>(
+ mDisplaySize, PixelCastJustification::LayoutDeviceIsScreenForBounds);
+ return ViewAs<ParentLayerPixel>(
+ ScreenSize(GetCompositionSize(displaySize)),
+ PixelCastJustification::ScreenIsParentLayerForRoot);
+}