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Diffstat (limited to 'widget/ContentCache.h')
| -rw-r--r-- | widget/ContentCache.h | 449 |
1 files changed, 449 insertions, 0 deletions
diff --git a/widget/ContentCache.h b/widget/ContentCache.h new file mode 100644 index 000000000..77a9d5617 --- /dev/null +++ b/widget/ContentCache.h @@ -0,0 +1,449 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- + * vim: sw=2 ts=8 et : + */ +/* 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_ContentCache_h +#define mozilla_ContentCache_h + +#include <stdint.h> + +#include "mozilla/Assertions.h" +#include "mozilla/CheckedInt.h" +#include "mozilla/EventForwards.h" +#include "mozilla/WritingModes.h" +#include "nsIWidget.h" +#include "nsString.h" +#include "nsTArray.h" +#include "Units.h" + +namespace mozilla { + +class ContentCacheInParent; + +/** + * ContentCache stores various information of the child content. + * This class has members which are necessary both in parent process and + * content process. + */ + +class ContentCache +{ +public: + typedef InfallibleTArray<LayoutDeviceIntRect> RectArray; + typedef widget::IMENotification IMENotification; + + ContentCache(); + +protected: + // Whole text in the target + nsString mText; + + // Start offset of the composition string. + uint32_t mCompositionStart; + + enum + { + ePrevCharRect = 1, + eNextCharRect = 0 + }; + + struct Selection final + { + // Following values are offset in "flat text". + uint32_t mAnchor; + uint32_t mFocus; + + WritingMode mWritingMode; + + // Character rects at previous and next character of mAnchor and mFocus. + // The reason why ContentCache needs to store each previous character of + // them is IME may query character rect of the last character of a line + // when caret is at the end of the line. + // Note that use ePrevCharRect and eNextCharRect for accessing each item. + LayoutDeviceIntRect mAnchorCharRects[2]; + LayoutDeviceIntRect mFocusCharRects[2]; + + // Whole rect of selected text. This is empty if the selection is collapsed. + LayoutDeviceIntRect mRect; + + Selection() + : mAnchor(UINT32_MAX) + , mFocus(UINT32_MAX) + { + } + + void Clear() + { + mAnchor = mFocus = UINT32_MAX; + mWritingMode = WritingMode(); + ClearAnchorCharRects(); + ClearFocusCharRects(); + mRect.SetEmpty(); + } + + void ClearAnchorCharRects() + { + for (size_t i = 0; i < ArrayLength(mAnchorCharRects); i++) { + mAnchorCharRects[i].SetEmpty(); + } + } + void ClearFocusCharRects() + { + for (size_t i = 0; i < ArrayLength(mFocusCharRects); i++) { + mFocusCharRects[i].SetEmpty(); + } + } + + bool IsValid() const + { + return mAnchor != UINT32_MAX && mFocus != UINT32_MAX; + } + bool Collapsed() const + { + NS_ASSERTION(IsValid(), + "The caller should check if the selection is valid"); + return mFocus == mAnchor; + } + bool Reversed() const + { + NS_ASSERTION(IsValid(), + "The caller should check if the selection is valid"); + return mFocus < mAnchor; + } + uint32_t StartOffset() const + { + NS_ASSERTION(IsValid(), + "The caller should check if the selection is valid"); + return Reversed() ? mFocus : mAnchor; + } + uint32_t EndOffset() const + { + NS_ASSERTION(IsValid(), + "The caller should check if the selection is valid"); + return Reversed() ? mAnchor : mFocus; + } + uint32_t Length() const + { + NS_ASSERTION(IsValid(), + "The caller should check if the selection is valid"); + return Reversed() ? mAnchor - mFocus : mFocus - mAnchor; + } + LayoutDeviceIntRect StartCharRect() const + { + NS_ASSERTION(IsValid(), + "The caller should check if the selection is valid"); + return Reversed() ? mFocusCharRects[eNextCharRect] : + mAnchorCharRects[eNextCharRect]; + } + LayoutDeviceIntRect EndCharRect() const + { + NS_ASSERTION(IsValid(), + "The caller should check if the selection is valid"); + return Reversed() ? mAnchorCharRects[eNextCharRect] : + mFocusCharRects[eNextCharRect]; + } + } mSelection; + + bool IsSelectionValid() const + { + return mSelection.IsValid() && mSelection.EndOffset() <= mText.Length(); + } + + // Stores first char rect because Yosemite's Japanese IME sometimes tries + // to query it. If there is no text, this is caret rect. + LayoutDeviceIntRect mFirstCharRect; + + struct Caret final + { + uint32_t mOffset; + LayoutDeviceIntRect mRect; + + Caret() + : mOffset(UINT32_MAX) + { + } + + void Clear() + { + mOffset = UINT32_MAX; + mRect.SetEmpty(); + } + + bool IsValid() const { return mOffset != UINT32_MAX; } + + uint32_t Offset() const + { + NS_ASSERTION(IsValid(), + "The caller should check if the caret is valid"); + return mOffset; + } + } mCaret; + + struct TextRectArray final + { + uint32_t mStart; + RectArray mRects; + + TextRectArray() + : mStart(UINT32_MAX) + { + } + + void Clear() + { + mStart = UINT32_MAX; + mRects.Clear(); + } + + bool IsValid() const + { + if (mStart == UINT32_MAX) { + return false; + } + CheckedInt<uint32_t> endOffset = + CheckedInt<uint32_t>(mStart) + mRects.Length(); + return endOffset.isValid(); + } + bool HasRects() const + { + return IsValid() && !mRects.IsEmpty(); + } + uint32_t StartOffset() const + { + NS_ASSERTION(IsValid(), + "The caller should check if the caret is valid"); + return mStart; + } + uint32_t EndOffset() const + { + NS_ASSERTION(IsValid(), + "The caller should check if the caret is valid"); + if (!IsValid()) { + return UINT32_MAX; + } + return mStart + mRects.Length(); + } + bool InRange(uint32_t aOffset) const + { + return IsValid() && + StartOffset() <= aOffset && aOffset < EndOffset(); + } + bool InRange(uint32_t aOffset, uint32_t aLength) const + { + CheckedInt<uint32_t> endOffset = + CheckedInt<uint32_t>(aOffset) + aLength; + if (NS_WARN_IF(!endOffset.isValid())) { + return false; + } + return InRange(aOffset) && aOffset + aLength <= EndOffset(); + } + bool IsOverlappingWith(uint32_t aOffset, uint32_t aLength) const + { + if (!HasRects() || aOffset == UINT32_MAX || !aLength) { + return false; + } + CheckedInt<uint32_t> endOffset = + CheckedInt<uint32_t>(aOffset) + aLength; + if (NS_WARN_IF(!endOffset.isValid())) { + return false; + } + return aOffset < EndOffset() && endOffset.value() > mStart; + } + LayoutDeviceIntRect GetRect(uint32_t aOffset) const; + LayoutDeviceIntRect GetUnionRect(uint32_t aOffset, uint32_t aLength) const; + LayoutDeviceIntRect GetUnionRectAsFarAsPossible( + uint32_t aOffset, uint32_t aLength, + bool aRoundToExistingOffset) const; + } mTextRectArray; + + LayoutDeviceIntRect mEditorRect; + + friend class ContentCacheInParent; + friend struct IPC::ParamTraits<ContentCache>; +}; + +class ContentCacheInChild final : public ContentCache +{ +public: + ContentCacheInChild(); + + /** + * When IME loses focus, this should be called and making this forget the + * content for reducing footprint. + */ + void Clear(); + + /** + * Cache*() retrieves the latest content information and store them. + * Be aware, CacheSelection() calls CacheTextRects(), and also CacheText() + * calls CacheSelection(). So, related data is also retrieved automatically. + */ + bool CacheEditorRect(nsIWidget* aWidget, + const IMENotification* aNotification = nullptr); + bool CacheSelection(nsIWidget* aWidget, + const IMENotification* aNotification = nullptr); + bool CacheText(nsIWidget* aWidget, + const IMENotification* aNotification = nullptr); + + bool CacheAll(nsIWidget* aWidget, + const IMENotification* aNotification = nullptr); + + /** + * SetSelection() modifies selection with specified raw data. And also this + * tries to retrieve text rects too. + */ + void SetSelection(nsIWidget* aWidget, + uint32_t aStartOffset, + uint32_t aLength, + bool aReversed, + const WritingMode& aWritingMode); + +private: + bool QueryCharRect(nsIWidget* aWidget, + uint32_t aOffset, + LayoutDeviceIntRect& aCharRect) const; + bool QueryCharRectArray(nsIWidget* aWidget, + uint32_t aOffset, + uint32_t aLength, + RectArray& aCharRectArray) const; + bool CacheCaret(nsIWidget* aWidget, + const IMENotification* aNotification = nullptr); + bool CacheTextRects(nsIWidget* aWidget, + const IMENotification* aNotification = nullptr); +}; + +class ContentCacheInParent final : public ContentCache +{ +public: + ContentCacheInParent(); + + /** + * AssignContent() is called when TabParent receives ContentCache from + * the content process. This doesn't copy composition information because + * it's managed by TabParent itself. + */ + void AssignContent(const ContentCache& aOther, + nsIWidget* aWidget, + const IMENotification* aNotification = nullptr); + + /** + * HandleQueryContentEvent() sets content data to aEvent.mReply. + * + * For eQuerySelectedText, fail if the cache doesn't contain the whole + * selected range. (This shouldn't happen because PuppetWidget should have + * already sent the whole selection.) + * + * For eQueryTextContent, fail only if the cache doesn't overlap with + * the queried range. Note the difference from above. We use + * this behavior because a normal eQueryTextContent event is allowed to + * have out-of-bounds offsets, so that widget can request content without + * knowing the exact length of text. It's up to widget to handle cases when + * the returned offset/length are different from the queried offset/length. + * + * For eQueryTextRect, fail if cached offset/length aren't equals to input. + * Cocoa widget always queries selected offset, so it works on it. + * + * For eQueryCaretRect, fail if cached offset isn't equals to input + * + * For eQueryEditorRect, always success + */ + bool HandleQueryContentEvent(WidgetQueryContentEvent& aEvent, + nsIWidget* aWidget) const; + + /** + * OnCompositionEvent() should be called before sending composition string. + * This returns true if the event should be sent. Otherwise, false. + */ + bool OnCompositionEvent(const WidgetCompositionEvent& aCompositionEvent); + + /** + * OnSelectionEvent() should be called before sending selection event. + */ + void OnSelectionEvent(const WidgetSelectionEvent& aSelectionEvent); + + /** + * OnEventNeedingAckHandled() should be called after the child process + * handles a sent event which needs acknowledging. + * + * WARNING: This may send notifications to IME. That might cause destroying + * TabParent or aWidget. Therefore, the caller must not destroy + * this instance during a call of this method. + */ + void OnEventNeedingAckHandled(nsIWidget* aWidget, EventMessage aMessage); + + /** + * RequestIMEToCommitComposition() requests aWidget to commit or cancel + * composition. If it's handled synchronously, this returns true. + * + * @param aWidget The widget to be requested to commit or cancel + * the composition. + * @param aCancel When the caller tries to cancel the composition, true. + * Otherwise, i.e., tries to commit the composition, false. + * @param aCommittedString The committed string (i.e., the last data of + * dispatched composition events during requesting + * IME to commit composition. + * @return Whether the composition is actually committed + * synchronously. + */ + bool RequestIMEToCommitComposition(nsIWidget* aWidget, + bool aCancel, + nsAString& aCommittedString); + + /** + * MaybeNotifyIME() may notify IME of the notification. If child process + * hasn't been handled all sending events yet, this stores the notification + * and flush it later. + */ + void MaybeNotifyIME(nsIWidget* aWidget, + const IMENotification& aNotification); + +private: + IMENotification mPendingSelectionChange; + IMENotification mPendingTextChange; + IMENotification mPendingLayoutChange; + IMENotification mPendingCompositionUpdate; + + // This is not nullptr only while the instance is requesting IME to + // composition. Then, data value of dispatched composition events should + // be stored into the instance. + nsAString* mCommitStringByRequest; + // mPendingEventsNeedingAck is increased before sending a composition event or + // a selection event and decreased after they are received in the child + // process. + uint32_t mPendingEventsNeedingAck; + // mCompositionStartInChild stores current composition start offset in the + // remote process. + uint32_t mCompositionStartInChild; + // mPendingCompositionCount is number of compositions which started in widget + // but not yet handled in the child process. + uint8_t mPendingCompositionCount; + // mWidgetHasComposition is true when the widget in this process thinks that + // IME has composition. So, this is set to true when eCompositionStart is + // dispatched and set to false when eCompositionCommit(AsIs) is dispatched. + bool mWidgetHasComposition; + + /** + * When following methods' aRoundToExistingOffset is true, even if specified + * offset or range is out of bounds, the result is computed with the existing + * cache forcibly. + */ + bool GetCaretRect(uint32_t aOffset, + bool aRoundToExistingOffset, + LayoutDeviceIntRect& aCaretRect) const; + bool GetTextRect(uint32_t aOffset, + bool aRoundToExistingOffset, + LayoutDeviceIntRect& aTextRect) const; + bool GetUnionTextRects(uint32_t aOffset, + uint32_t aLength, + bool aRoundToExistingOffset, + LayoutDeviceIntRect& aUnionTextRect) const; + + void FlushPendingNotifications(nsIWidget* aWidget); +}; + +} // namespace mozilla + +#endif // mozilla_ContentCache_h |