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Diffstat (limited to 'layout/base/MobileViewportManager.h')
| -rw-r--r-- | layout/base/MobileViewportManager.h | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/layout/base/MobileViewportManager.h b/layout/base/MobileViewportManager.h new file mode 100644 index 0000000000..1d4fba1d54 --- /dev/null +++ b/layout/base/MobileViewportManager.h @@ -0,0 +1,220 @@ +/* -*- 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/. */ + +#ifndef MobileViewportManager_h_ +#define MobileViewportManager_h_ + +#include "mozilla/Logging.h" +#include "mozilla/Maybe.h" +#include "mozilla/MVMContext.h" +#include "mozilla/PresShellForwards.h" +#include "nsCOMPtr.h" +#include "nsIDOMEventListener.h" +#include "nsIObserver.h" +#include "Units.h" + +class nsViewportInfo; + +namespace mozilla { +class MVMContext; +namespace dom { +class Document; +class EventTarget; +} // namespace dom +} // namespace mozilla + +class MobileViewportManager final : public nsIDOMEventListener, + public nsIObserver { + public: + NS_DECL_ISUPPORTS + NS_DECL_NSIDOMEVENTLISTENER + NS_DECL_NSIOBSERVER + + /* The MobileViewportManager might be required to handle meta-viewport tags + * and changes, or it might not (e.g. if we are in a desktop-zooming setup). + * This enum indicates which mode the manager is in. It might make sense to + * split these two "modes" into two separate classes but for now they have a + * bunch of shared code and it's uncertain if that shared set will expand or + * contract. */ + enum class ManagerType { VisualAndMetaViewport, VisualViewportOnly }; + + explicit MobileViewportManager(mozilla::MVMContext* aContext, + ManagerType aType); + void Destroy(); + + ManagerType GetManagerType() { return mManagerType; } + + /* Provide a resolution to use during the first paint instead of the default + * resolution computed from the viewport info metadata. This is in the same + * "units" as the argument to nsDOMWindowUtils::SetResolutionAndScaleTo. + * Also takes the previous display dimensions as they were at the time the + * resolution was stored in order to correctly adjust the resolution if the + * device was rotated in the meantime. */ + void SetRestoreResolution(float aResolution, + mozilla::LayoutDeviceIntSize aDisplaySize); + + /* Compute the "intrinsic resolution", which is the smallest resolution at + * which the layout viewport fills the visual viewport. (In typical + * scenarios, where the aspect ratios of the two viewports match, it's the + * resolution at which they are the same size.) + * + * The returned resolution is suitable for passing to + * PresShell::SetResolutionAndScaleTo(). It's not in typed units for + * reasons explained at the declaration of FrameMetrics::mPresShellResolution. + */ + float ComputeIntrinsicResolution() const; + + /* The only direct calls to this should be in test code. + * Normally, it gets called by HandleEvent(). + */ + void HandleDOMMetaAdded(); + + private: + void SetRestoreResolution(float aResolution); + + public: + /* Notify the MobileViewportManager that a reflow is about to happen. This + * triggers the MVM to update its internal notion of display size and CSS + * viewport, so that code that queries those during the reflow gets an + * up-to-date value. + */ + void UpdateSizesBeforeReflow(); + + /* Notify the MobileViewportManager that a reflow was requested in the + * presShell.*/ + void RequestReflow(bool aForceAdjustResolution); + + /* Notify the MobileViewportManager that the resolution on the presShell was + * updated, and the visual viewport size needs to be updated. */ + void ResolutionUpdated(mozilla::ResolutionChangeOrigin aOrigin); + + /* Called to compute the initial viewport on page load or before-first-paint, + * whichever happens first. Also called directly if we are created after the + * presShell is initialized. */ + void SetInitialViewport(); + + const mozilla::LayoutDeviceIntSize& DisplaySize() const { + return mDisplaySize; + }; + + /* + * Shrink the content to fit it to the display width if no initial-scale is + * specified and if the content is still wider than the display width. + */ + void ShrinkToDisplaySizeIfNeeded(); + + /* + * Similar to UpdateVisualViewportSize but this should be called only when we + * need to update visual viewport size in response to dynamic toolbar + * transitions. + * This function doesn't cause any reflows, just fires a visual viewport + * resize event. + */ + void UpdateVisualViewportSizeByDynamicToolbar( + mozilla::ScreenIntCoord aToolbarHeight); + + nsSize GetVisualViewportSizeUpdatedByDynamicToolbar() const { + return mVisualViewportSizeUpdatedByDynamicToolbar; + } + + /* + * This refreshes the visual viewport size based on the most recently + * available information. It is intended to be called in particular after + * the root scrollframe does a reflow, which may make scrollbars appear or + * disappear if the content changed size. + */ + void UpdateVisualViewportSizeForPotentialScrollbarChange(); + + /* + * Returns the composition size in CSS units when zoomed to the intrinsic + * scale. + */ + mozilla::CSSSize GetIntrinsicCompositionSize() const; + + mozilla::ParentLayerSize GetCompositionSizeWithoutDynamicToolbar() const; + + static mozilla::LazyLogModule gLog; + + private: + ~MobileViewportManager(); + + /* Main helper method to update the CSS viewport and any other properties that + * need updating. */ + void RefreshViewportSize(bool aForceAdjustResolution); + + /* Secondary main helper method to update just the visual viewport size. */ + void RefreshVisualViewportSize(); + + /* Helper to clamp the given zoom by the min/max in the viewport info. */ + mozilla::CSSToScreenScale ClampZoom( + const mozilla::CSSToScreenScale& aZoom, + const nsViewportInfo& aViewportInfo) const; + + /* Helper to update the given zoom according to changed display and viewport + * widths. */ + mozilla::CSSToScreenScale ScaleZoomWithDisplayWidth( + const mozilla::CSSToScreenScale& aZoom, + const float& aDisplayWidthChangeRatio, + const mozilla::CSSSize& aNewViewport, + const mozilla::CSSSize& aOldViewport); + + mozilla::CSSToScreenScale ResolutionToZoom( + const mozilla::LayoutDeviceToLayerScale& aResolution) const; + mozilla::LayoutDeviceToLayerScale ZoomToResolution( + const mozilla::CSSToScreenScale& aZoom) const; + + /* Updates the presShell resolution and the visual viewport size for various + * types of changes. */ + void UpdateResolutionForFirstPaint(const mozilla::CSSSize& aViewportSize); + void UpdateResolutionForViewportSizeChange( + const mozilla::CSSSize& aViewportSize, + const mozilla::Maybe<float>& aDisplayWidthChangeRatio); + void UpdateResolutionForContentSizeChange( + const mozilla::CSSSize& aContentSize); + + void ApplyNewZoom(const mozilla::ScreenIntSize& aDisplaySize, + const mozilla::CSSToScreenScale& aNewZoom); + + void UpdateVisualViewportSize(const mozilla::ScreenIntSize& aDisplaySize, + const mozilla::CSSToScreenScale& aZoom); + + /* Updates the displayport margins for the presShell's root scrollable frame + */ + void UpdateDisplayPortMargins(); + + /* Helper function for ComputeIntrinsicResolution(). */ + mozilla::CSSToScreenScale ComputeIntrinsicScale( + const nsViewportInfo& aViewportInfo, + const mozilla::ScreenIntSize& aDisplaySize, + const mozilla::CSSSize& aViewportOrContentSize) const; + + /* + * Returns the screen size subtracted the scrollbar sizes from |aDisplaySize|. + */ + mozilla::ScreenIntSize GetCompositionSize( + const mozilla::ScreenIntSize& aDisplaySize) const; + + mozilla::CSSToScreenScale GetZoom() const; + + RefPtr<mozilla::MVMContext> mContext; + ManagerType mManagerType; + bool mIsFirstPaint; + bool mPainted; + mozilla::LayoutDeviceIntSize mDisplaySize; + mozilla::CSSSize mMobileViewportSize; + mozilla::Maybe<float> mRestoreResolution; + mozilla::Maybe<mozilla::ScreenIntSize> mRestoreDisplaySize; + /* + * The visual viewport size updated by the dynamic toolbar transitions. This + * is typically used for the VisualViewport width/height APIs. + * NOTE: If you want to use this value, you should make sure to flush + * position:fixed elements layout and update + * FrameMetrics.mFixedLayerMargins to conform with this value. + */ + nsSize mVisualViewportSizeUpdatedByDynamicToolbar; +}; + +#endif |