From 6bf0a5cb5034a7e684dcc3500e841785237ce2dd Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 19:32:43 +0200 Subject: Adding upstream version 1:115.7.0. Signed-off-by: Daniel Baumann --- layout/base/ViewportUtils.h | 128 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 128 insertions(+) create mode 100644 layout/base/ViewportUtils.h (limited to 'layout/base/ViewportUtils.h') diff --git a/layout/base/ViewportUtils.h b/layout/base/ViewportUtils.h new file mode 100644 index 0000000000..bc65119f29 --- /dev/null +++ b/layout/base/ViewportUtils.h @@ -0,0 +1,128 @@ +/* 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 mozilla_ViewportUtils_h +#define mozilla_ViewportUtils_h + +#include "Units.h" +#include "mozilla/layers/ScrollableLayerGuid.h" + +class nsIFrame; +class nsPresContext; + +namespace mozilla { + +class PresShell; + +class ViewportUtils { + public: + /* Return a transform to be applied to the coordinates of input events + targeting content inside the scroll frame identified by |aScrollId|, which + converts from "visual coordinates" (which are the coordinates events have + when they arrive from APZ) to "layout coordinates" (which are the + coordinates used in most places by layout code). The transform has two + components: + 1. The pres shell resolution, representing the pinch-zoom scale + (if the scroll frame |aScrollId| is inside the resolution, which + is most of the time). + 2. A translation representing async scrolling. This can contain: + - For any scroll frame, a scroll component resulting from the main + thread incompletely applying an APZ-requested scroll position. + - For the RCD-RSF only, a persistent component representing the + offset of the visual viewport relative to the layout viewport. + The translation is accumulated for all scroll frames form |aScrollId| + up to the root, using values populated in + APZCCallbackHelper::UpdateCallbackTransform. See that method's + documentation for additional details. */ + template + static gfx::Matrix4x4Typed GetVisualToLayoutTransform( + layers::ScrollableLayerGuid::ViewID aScrollId); + + /* The functions below apply GetVisualToLayoutTransform() or its inverse + * to various quantities. + * + * To determine the appropriate scroll id to pass into + * GetVisualToLayoutTransform(), these functions prefer to use the one + * from InputAPZContext::GetTargetLayerGuid() if one is available. + * If one is not available, they use the scroll id of the root scroll + * frame of the pres shell passed in as |aContext| as a fallback. + */ + static nsPoint VisualToLayout(const nsPoint& aPt, PresShell* aContext); + static nsRect VisualToLayout(const nsRect& aRect, PresShell* aContext); + static nsPoint LayoutToVisual(const nsPoint& aPt, PresShell* aContext); + + /* + * These functions convert the point/rect from layout to visual space + * by applying the inverse of GetLayoutToVisualTransform() of the root + * scrollframe of provided presShell. + */ + static LayoutDevicePoint DocumentRelativeLayoutToVisual( + const LayoutDevicePoint& aPoint, PresShell* aShell); + static LayoutDeviceRect DocumentRelativeLayoutToVisual( + const LayoutDeviceRect& aRect, PresShell* aShell); + static LayoutDeviceRect DocumentRelativeLayoutToVisual( + const LayoutDeviceIntRect& aRect, PresShell* aShell); + static CSSRect DocumentRelativeLayoutToVisual(const CSSRect& aRect, + PresShell* aShell); + + /* + * These convert aPt/aRect, which is the layout space of aCtx, into a + * screen-relative visual-space quantity. Formally, we can think of the input + * as being in RelativeTo{aCtx->PresShell()->GetRootFrame(), + * ViewportType::Layout} space. And then the function iterates up the chain of + * presContexts, transforming the point along, until it gets to the + * RelativeTo{aCtx->GetRootPresContext()->PresShell()->GetRootFrame(), + * ViewportType::Visual} space. Then it further transforms it into a + * screen-relative space. Unlike the GetTransformToAncestor family of helper + * methods, this transformation does NOT include CSS transforms. Also, unlike + * other ViewportUtils methods, the input is relative to `aCtx` which might be + * a sub-shell of the presShell with the resolution. + */ + static LayoutDevicePoint ToScreenRelativeVisual(const LayoutDevicePoint& aPt, + nsPresContext* aCtx); + static LayoutDeviceRect ToScreenRelativeVisual(const LayoutDeviceRect& aRect, + nsPresContext* aCtx); + + /** + * Returns non-null if |aFrame| is inside the async zoom container but its + * parent frame is not, thereby making |aFrame| a root of a subtree of + * frames representing content that is zoomed in. The value returned in such + * cases is the root scroll frame inside the async zoom container. + + * Callers use this to identify points during frame tree traversal where the + * visual-to-layout transform needs to be applied. + */ + static const nsIFrame* IsZoomedContentRoot(const nsIFrame* aFrame); + + /** + * If |aShell| is in a nested content process, try to infer the resolution + * at which the enclosing root content + * document has been painted. + * + * Otherwise (if |aShell| is in the chrome or top-level content process), + * this function returns 1.0. + * + * |aShell| must be the root pres shell in its process. + * + * This function may not return an accurate answer if there is also + * a CSS transform enclosing the iframe. + */ + static Scale2D TryInferEnclosingResolution(PresShell* aShell); +}; + +// Forward declare explicit instantiations of GetVisualToLayoutTransform() for +// CSSPixel and LayoutDevicePixel, the only two types it gets used with. +// These declarations promise to callers in any translation unit that _some_ +// translation unit (in this case, ViewportUtils.cpp) will contain the +// definitions of these instantiations. This allows us to keep the definition +// out-of-line in the source. +extern template CSSToCSSMatrix4x4 ViewportUtils::GetVisualToLayoutTransform< + CSSPixel>(layers::ScrollableLayerGuid::ViewID); +extern template LayoutDeviceToLayoutDeviceMatrix4x4 + ViewportUtils::GetVisualToLayoutTransform( + layers::ScrollableLayerGuid::ViewID); + +} // namespace mozilla + +#endif /* mozilla_ViewportUtils_h */ -- cgit v1.2.3