/* -*- 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 AccessibleCaret_h__ #define AccessibleCaret_h__ #include "mozilla/Attributes.h" #include "mozilla/dom/AnonymousContent.h" #include "mozilla/dom/Element.h" #include "nsCOMPtr.h" #include "nsIDOMEventListener.h" #include "nsISupportsBase.h" #include "nsISupportsImpl.h" #include "nsLiteralString.h" #include "nsRect.h" #include "mozilla/RefPtr.h" #include "nsString.h" class nsIDocument; class nsIFrame; class nsIPresShell; struct nsPoint; namespace mozilla { // ----------------------------------------------------------------------------- // Upon the creation of AccessibleCaret, it will insert DOM Element as an // anonymous content containing the caret image. The caret appearance and // position can be controlled by SetAppearance() and SetPosition(). // // All the rect or point are relative to root frame except being specified // explicitly. // // None of the methods in AccessibleCaret will flush layout or style. To ensure // that SetPosition() works correctly, the caller must make sure the layout is // up to date. // // Please see the wiki page for more information. // https://wiki.mozilla.org/AccessibleCaret // class AccessibleCaret { public: explicit AccessibleCaret(nsIPresShell* aPresShell); virtual ~AccessibleCaret(); // This enumeration representing the visibility and visual style of an // AccessibleCaret. // // Use SetAppearance() to change the appearance, and use GetAppearance() to // get the current appearance. enum class Appearance : uint8_t { // Do not display the caret at all. None, // Display the caret in default style. Normal, // The caret should be displayed logically but it is kept invisible to the // user. This enum is the only difference between "logically visible" and // "visually visible". It can be used for reasons such as: // 1. Out of scroll port. // 2. For UX requirement such as hide a caret in an empty text area. NormalNotShown, // Display the caret which is tilted to the left. Left, // Display the caret which is tilted to the right. Right }; friend std::ostream& operator<<(std::ostream& aStream, const Appearance& aAppearance); Appearance GetAppearance() const { return mAppearance; } virtual void SetAppearance(Appearance aAppearance); // Return true if current appearance is either Normal, NormalNotShown, Left, // or Right. bool IsLogicallyVisible() const { return mAppearance != Appearance::None; } // Return true if current appearance is either Normal, Left, or Right. bool IsVisuallyVisible() const { return (mAppearance != Appearance::None) && (mAppearance != Appearance::NormalNotShown); } // Set true to enable the "Text Selection Bar" described in "Text Selection // Visual Spec" in bug 921965. virtual void SetSelectionBarEnabled(bool aEnabled); // This enumeration representing the result returned by SetPosition(). enum class PositionChangedResult : uint8_t { // Position is not changed. NotChanged, // Position or zoom level is changed. Changed, // Position is out of scroll port. Invisible }; friend std::ostream& operator<<(std::ostream& aStream, const PositionChangedResult& aResult); virtual PositionChangedResult SetPosition(nsIFrame* aFrame, int32_t aOffset); // Does two AccessibleCarets overlap? bool Intersects(const AccessibleCaret& aCaret) const; // Is the point within the caret's rect? The point should be relative to root // frame. enum class TouchArea { Full, // Contains both text overlay and caret image. CaretImage }; bool Contains(const nsPoint& aPoint, TouchArea aTouchArea) const; // The geometry center of the imaginary caret (nsCaret) to which this // AccessibleCaret is attached. It is needed when dragging the caret. nsPoint LogicalPosition() const { return mImaginaryCaretRect.Center(); } // Element for 'Intersects' test. Container of image and bar elements. dom::Element* CaretElement() const { return mCaretElementHolder->GetContentNode(); } // Ensures that the caret element is made "APZ aware" so that the APZ code // doesn't scroll the page when the user is trying to drag the caret. void EnsureApzAware(); protected: // Argument aRect should be relative to CustomContentContainerFrame(). void SetCaretElementStyle(const nsRect& aRect, float aZoomLevel); void SetTextOverlayElementStyle(const nsRect& aRect, float aZoomLevel); void SetCaretImageElementStyle(const nsRect& aRect, float aZoomLevel); void SetSelectionBarElementStyle(const nsRect& aRect, float aZoomLevel); // Get current zoom level. float GetZoomLevel(); // Element which contains the text overly for the 'Contains' test. dom::Element* TextOverlayElement() const { return mCaretElementHolder->GetElementById(sTextOverlayElementId); } // Element which contains the caret image for 'Contains' test. dom::Element* CaretImageElement() const { return mCaretElementHolder->GetElementById(sCaretImageElementId); } // Element which represents the text selection bar. dom::Element* SelectionBarElement() const { return mCaretElementHolder->GetElementById(sSelectionBarElementId); } nsIFrame* RootFrame() const { return mPresShell->GetRootFrame(); } nsIFrame* CustomContentContainerFrame() const; // Transform Appearance to CSS id used in ua.css. static nsAutoString AppearanceString(Appearance aAppearance); already_AddRefed<dom::Element> CreateCaretElement(nsIDocument* aDocument) const; // Inject caret element into custom content container. void InjectCaretElement(nsIDocument* aDocument); // Remove caret element from custom content container. void RemoveCaretElement(nsIDocument* aDocument); // The top-center of the imaginary caret to which this AccessibleCaret is // attached. static nsPoint CaretElementPosition(const nsRect& aRect) { return aRect.TopLeft() + nsPoint(aRect.width / 2, 0); } class DummyTouchListener final : public nsIDOMEventListener { public: NS_DECL_ISUPPORTS NS_IMETHOD HandleEvent(nsIDOMEvent* aEvent) override { return NS_OK; } private: virtual ~DummyTouchListener() {}; }; // Member variables Appearance mAppearance = Appearance::None; bool mSelectionBarEnabled = false; // AccessibleCaretManager owns us by a UniquePtr. When it's terminated by // AccessibleCaretEventHub::Terminate() which is called in // PresShell::Destroy(), it frees us automatically. No need to worry if we // outlive mPresShell. nsIPresShell* MOZ_NON_OWNING_REF const mPresShell = nullptr; RefPtr<dom::AnonymousContent> mCaretElementHolder; // mImaginaryCaretRect is relative to root frame. nsRect mImaginaryCaretRect; // Cache current zoom level to determine whether position is changed. float mZoomLevel = 0.0f; // A no-op touch-start listener which prevents APZ from panning when dragging // the caret. RefPtr<DummyTouchListener> mDummyTouchListener{new DummyTouchListener()}; // Static class variables static float sWidth; static float sHeight; static float sMarginLeft; static float sBarWidth; static const nsLiteralString sTextOverlayElementId; static const nsLiteralString sCaretImageElementId; static const nsLiteralString sSelectionBarElementId; }; // class AccessibleCaret std::ostream& operator<<(std::ostream& aStream, const AccessibleCaret::Appearance& aAppearance); std::ostream& operator<<(std::ostream& aStream, const AccessibleCaret::PositionChangedResult& aResult); } // namespace mozilla #endif // AccessibleCaret_h__