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Diffstat (limited to 'layout/base/MobileViewportManager.cpp')
| -rw-r--r-- | layout/base/MobileViewportManager.cpp | 752 |
1 files changed, 752 insertions, 0 deletions
diff --git a/layout/base/MobileViewportManager.cpp b/layout/base/MobileViewportManager.cpp new file mode 100644 index 0000000000..0b37430d39 --- /dev/null +++ b/layout/base/MobileViewportManager.cpp @@ -0,0 +1,752 @@ +/* -*- 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); +} |