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      1 /*
      2  * Copyright (C) 2010 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 WebScrollbar_h
     32 #define WebScrollbar_h
     33 
     34 #include "WebCanvas.h"
     35 #include "WebCommon.h"
     36 
     37 namespace WebKit {
     38 
     39 class WebInputEvent;
     40 class WebScrollbarClient;
     41 struct WebRect;
     42 
     43 class WebScrollbar {
     44 public:
     45     enum Orientation {
     46         Horizontal,
     47         Vertical
     48     };
     49 
     50     enum ScrollDirection {
     51         ScrollBackward,
     52         ScrollForward
     53     };
     54 
     55     enum ScrollGranularity {
     56         ScrollByLine,
     57         ScrollByPage,
     58         ScrollByDocument,
     59         ScrollByPixel
     60     };
     61 
     62     // Creates a WebScrollbar.
     63     WEBKIT_API static WebScrollbar* create(WebScrollbarClient*, Orientation);
     64 
     65     virtual ~WebScrollbar() {}
     66 
     67     // Gets the thickness of the scrollbar in pixels.
     68     WEBKIT_API static int defaultThickness();
     69 
     70     // Sets the rectangle of the scrollbar.
     71     virtual void setLocation(const WebRect&) = 0;
     72 
     73     // Gets the current value (i.e. position inside the region).
     74     virtual int value() const = 0;
     75 
     76     // Sets the current value.
     77     virtual void setValue(int position) = 0;
     78 
     79     // Sets the size of the scrollable region in pixels.  i.e. if a document is
     80     // 800x10000 pixels and the viewport is 1000x1000 pixels, then setLocation
     81     // for the vertical scrollbar would have passed in a rectangle like:
     82     //            (800 - defaultThickness(), 0) (defaultThickness() x 10000)
     83     // and setDocumentSize(10000)
     84     virtual void setDocumentSize(int size) = 0;
     85 
     86     // Scroll back or forward with the given granularity.
     87     virtual void scroll(ScrollDirection, ScrollGranularity, float multiplier) = 0;
     88 
     89     // Paint the given rectangle.
     90     virtual void paint(WebCanvas*, const WebRect&) = 0;
     91 
     92     // Returns true iff the given event was used.
     93     virtual bool handleInputEvent(const WebInputEvent&) = 0;
     94 };
     95 
     96 } // namespace WebKit
     97 
     98 #endif
     99