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      1 /*
      2  * Copyright (C) 2009 Google Inc. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions are
      6  * met:
      7  *
      8  *     * Redistributions of source code must retain the above copyright
      9  * notice, this list of conditions and the following disclaimer.
     10  *     * Redistributions in binary form must reproduce the above
     11  * copyright notice, this list of conditions and the following disclaimer
     12  * in the documentation and/or other materials provided with the
     13  * distribution.
     14  *     * Neither the name of Google Inc. nor the names of its
     15  * contributors may be used to endorse or promote products derived from
     16  * this software without specific prior written permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     29  */
     30 
     31 #ifndef TextFinder_h
     32 #define TextFinder_h
     33 
     34 #include "core/editing/FindOptions.h"
     35 #include "platform/geometry/FloatRect.h"
     36 #include "platform/heap/Handle.h"
     37 #include "public/platform/WebFloatPoint.h"
     38 #include "public/platform/WebFloatRect.h"
     39 #include "public/platform/WebRect.h"
     40 #include "public/web/WebFindOptions.h"
     41 #include "wtf/PassOwnPtr.h"
     42 #include "wtf/PassRefPtr.h"
     43 #include "wtf/Vector.h"
     44 #include "wtf/text/WTFString.h"
     45 
     46 namespace WebCore {
     47 class Range;
     48 }
     49 
     50 namespace blink {
     51 class WebLocalFrameImpl;
     52 
     53 template <typename T> class WebVector;
     54 
     55 class TextFinder {
     56 public:
     57     static PassOwnPtr<TextFinder> create(WebLocalFrameImpl& ownerFrame);
     58 
     59     bool find(
     60         int identifier, const WebString& searchText, const WebFindOptions&,
     61         bool wrapWithinFrame, WebRect* selectionRect);
     62     void stopFindingAndClearSelection();
     63     void scopeStringMatches(
     64         int identifier, const WebString& searchText, const WebFindOptions&,
     65         bool reset);
     66     void cancelPendingScopingEffort();
     67     void increaseMatchCount(int identifier, int count);
     68     void resetMatchCount();
     69     int findMatchMarkersVersion() const { return m_findMatchMarkersVersion; }
     70     WebFloatRect activeFindMatchRect();
     71     void findMatchRects(WebVector<WebFloatRect>&);
     72     int selectNearestFindMatch(const WebFloatPoint&, WebRect* selectionRect);
     73 
     74     // Returns which frame has an active match. This function should only be
     75     // called on the main frame, as it is the only frame keeping track. Returned
     76     // value can be 0 if no frame has an active match.
     77     WebLocalFrameImpl* activeMatchFrame() const { return m_currentActiveMatchFrame; }
     78 
     79     // Returns the active match in the current frame. Could be a null range if
     80     // the local frame has no active match.
     81     WebCore::Range* activeMatch() const { return m_activeMatch.get(); }
     82 
     83     void flushCurrentScoping();
     84 
     85     void resetActiveMatch() { m_activeMatch = nullptr; }
     86 
     87     int totalMatchCount() const { return m_totalMatchCount; }
     88     bool scopingInProgress() const { return m_scopingInProgress; }
     89     void increaseMarkerVersion() { ++m_findMatchMarkersVersion; }
     90 
     91     ~TextFinder();
     92 
     93     class FindMatch {
     94         ALLOW_ONLY_INLINE_ALLOCATION();
     95     public:
     96         RefPtrWillBeMember<WebCore::Range> m_range;
     97 
     98         // 1-based index within this frame.
     99         int m_ordinal;
    100 
    101         // In find-in-page coordinates.
    102         // Lazily calculated by updateFindMatchRects.
    103         WebCore::FloatRect m_rect;
    104 
    105         FindMatch(PassRefPtrWillBeRawPtr<WebCore::Range>, int ordinal);
    106 
    107         void trace(WebCore::Visitor*);
    108     };
    109 
    110 private:
    111     class DeferredScopeStringMatches;
    112     friend class DeferredScopeStringMatches;
    113 
    114     explicit TextFinder(WebLocalFrameImpl& ownerFrame);
    115 
    116     // Notifies the delegate about a new selection rect.
    117     void reportFindInPageSelection(
    118         const WebRect& selectionRect, int activeMatchOrdinal, int identifier);
    119 
    120     // Clear the find-in-page matches cache forcing rects to be fully
    121     // calculated again next time updateFindMatchRects is called.
    122     void clearFindMatchesCache();
    123 
    124     // Check if the activeMatchFrame still exists in the frame tree.
    125     bool isActiveMatchFrameValid() const;
    126 
    127     // Return the index in the find-in-page cache of the match closest to the
    128     // provided point in find-in-page coordinates, or -1 in case of error.
    129     // The squared distance to the closest match is returned in the distanceSquared parameter.
    130     int nearestFindMatch(const WebCore::FloatPoint&, float& distanceSquared);
    131 
    132     // Select a find-in-page match marker in the current frame using a cache
    133     // match index returned by nearestFindMatch. Returns the ordinal of the new
    134     // selected match or -1 in case of error. Also provides the bounding box of
    135     // the marker in window coordinates if selectionRect is not null.
    136     int selectFindMatch(unsigned index, WebRect* selectionRect);
    137 
    138     // Compute and cache the rects for FindMatches if required.
    139     // Rects are automatically invalidated in case of content size changes,
    140     // propagating the invalidation to child frames.
    141     void updateFindMatchRects();
    142 
    143     // Append the find-in-page match rects of the current frame to the provided vector.
    144     void appendFindMatchRects(Vector<WebFloatRect>& frameRects);
    145 
    146     // Add a WebKit TextMatch-highlight marker to nodes in a range.
    147     void addMarker(WebCore::Range*, bool activeMatch);
    148 
    149     // Sets the markers within a range as active or inactive.
    150     void setMarkerActive(WebCore::Range*, bool active);
    151 
    152     // Returns the ordinal of the first match in the frame specified. This
    153     // function enumerates the frames, starting with the main frame and up to (but
    154     // not including) the frame passed in as a parameter and counts how many
    155     // matches have been found.
    156     int ordinalOfFirstMatchForFrame(WebLocalFrameImpl*) const;
    157 
    158     // Determines whether the scoping effort is required for a particular frame.
    159     // It is not necessary if the frame is invisible, for example, or if this
    160     // is a repeat search that already returned nothing last time the same prefix
    161     // was searched.
    162     bool shouldScopeMatches(const WTF::String& searchText);
    163 
    164     // Removes the current frame from the global scoping effort and triggers any
    165     // updates if appropriate. This method does not mark the scoping operation
    166     // as finished.
    167     void flushCurrentScopingEffort(int identifier);
    168 
    169     // Finishes the current scoping effort and triggers any updates if appropriate.
    170     void finishCurrentScopingEffort(int identifier);
    171 
    172     // Queue up a deferred call to scopeStringMatches.
    173     void scopeStringMatchesSoon(
    174         int identifier, const WebString& searchText, const WebFindOptions&,
    175         bool reset);
    176 
    177     // Called by a DeferredScopeStringMatches instance.
    178     void callScopeStringMatches(
    179         DeferredScopeStringMatches*, int identifier, const WebString& searchText,
    180         const WebFindOptions&, bool reset);
    181 
    182     // Determines whether to invalidate the content area and scrollbar.
    183     void invalidateIfNecessary();
    184 
    185     // Sets the markers within a current match range as active or inactive.
    186     void setMatchMarkerActive(bool);
    187 
    188     void decrementFramesScopingCount(int identifier);
    189 
    190     // Returns the ordinal of the first match in the owner frame.
    191     int ordinalOfFirstMatch() const;
    192 
    193     WebLocalFrameImpl& m_ownerFrame;
    194 
    195     // A way for the main frame to keep track of which frame has an active
    196     // match. Should be 0 for all other frames.
    197     WebLocalFrameImpl* m_currentActiveMatchFrame;
    198 
    199     // The range of the active match for the current frame.
    200     RefPtrWillBePersistent<WebCore::Range> m_activeMatch;
    201 
    202     // The index of the active match for the current frame.
    203     int m_activeMatchIndexInCurrentFrame;
    204 
    205     // The scoping effort can time out and we need to keep track of where we
    206     // ended our last search so we can continue from where we left of.
    207     //
    208     // This range is collapsed to the start position of the last successful
    209     // search; the new search should start from the next adjacent position.
    210     RefPtrWillBePersistent<WebCore::Range> m_resumeScopingFromRange;
    211 
    212     // Keeps track of the last string this frame searched for. This is used for
    213     // short-circuiting searches in the following scenarios: When a frame has
    214     // been searched and returned 0 results, we don't need to search that frame
    215     // again if the user is just adding to the search (making it more specific).
    216     WTF::String m_lastSearchString;
    217 
    218     // Keeps track of how many matches this frame has found so far, so that we
    219     // don't loose count between scoping efforts, and is also used (in conjunction
    220     // with m_lastSearchString) to figure out if we need to search the frame again.
    221     int m_lastMatchCount;
    222 
    223     // This variable keeps a cumulative total of matches found so far for ALL the
    224     // frames on the page, and is only incremented by calling IncreaseMatchCount
    225     // (on the main frame only). It should be -1 for all other frames.
    226     int m_totalMatchCount;
    227 
    228     // This variable keeps a cumulative total of how many frames are currently
    229     // scoping, and is incremented/decremented on the main frame only.
    230     // It should be -1 for all other frames.
    231     int m_framesScopingCount;
    232 
    233     // Identifier of the latest find-in-page request. Required to be stored in
    234     // the frame in order to reply if required in case the frame is detached.
    235     int m_findRequestIdentifier;
    236 
    237     // Keeps track of when the scoping effort should next invalidate the scrollbar
    238     // and the frame area.
    239     int m_nextInvalidateAfter;
    240 
    241     // A list of all of the pending calls to scopeStringMatches.
    242     Vector<DeferredScopeStringMatches*> m_deferredScopingWork;
    243 
    244     // Version number incremented on the main frame only whenever the document
    245     // find-in-page match markers change. It should be 0 for all other frames.
    246     int m_findMatchMarkersVersion;
    247 
    248     // Local cache of the find match markers currently displayed for this frame.
    249     WillBePersistentHeapVector<FindMatch> m_findMatchesCache;
    250 
    251     // Contents size when find-in-page match rects were last computed for this
    252     // frame's cache.
    253     WebCore::IntSize m_contentsSizeForCurrentFindMatchRects;
    254 
    255     // This flag is used by the scoping effort to determine if we need to figure
    256     // out which rectangle is the active match. Once we find the active
    257     // rectangle we clear this flag.
    258     bool m_locatingActiveRect;
    259 
    260     // Keeps track of whether there is an scoping effort ongoing in the frame.
    261     bool m_scopingInProgress;
    262 
    263     // Keeps track of whether the last find request completed its scoping effort
    264     // without finding any matches in this frame.
    265     bool m_lastFindRequestCompletedWithNoMatches;
    266 
    267     // Determines if the rects in the find-in-page matches cache of this frame
    268     // are invalid and should be recomputed.
    269     bool m_findMatchRectsAreValid;
    270 };
    271 
    272 } // namespace blink
    273 
    274 namespace WTF {
    275 template <> struct VectorTraits<blink::TextFinder::FindMatch> : VectorTraitsBase<blink::TextFinder::FindMatch> {
    276     static const bool canInitializeWithMemset = true;
    277 };
    278 }
    279 
    280 #endif
    281