src/kits/interface/textview_support/LineBuffer.cpp

   1 /*
   2  * Copyright 2001-2006, Haiku, Inc. All Rights Reserved.
   3  * Distributed under the terms of the MIT License.
   4  *
   5  * Authors:
   6  *              Marc Flerackers (mflerackers@androme.be)
   7  */
   8
   9
  10 #include "LineBuffer.h"
  11
  12
  13 BTextView::LineBuffer::LineBuffer()
  14         :       _BTextViewSupportBuffer_<STELine>(20, 2)
  15 {
  16 }
  17
  18
  19 BTextView::LineBuffer::~LineBuffer()
  20 {
  21 }
  22
  23
  24 void
  25 BTextView::LineBuffer::InsertLine(STELine* inLine, int32 index)
  26 {
  27         InsertItemsAt(1, index, inLine);
  28 }
  29
  30
  31 void
  32 BTextView::LineBuffer::RemoveLines(int32 index, int32 count)
  33 {
  34         RemoveItemsAt(count, index);
  35 }
  36
  37
  38 void
  39 BTextView::LineBuffer::RemoveLineRange(int32 fromOffset, int32 toOffset)
  40 {
  41         int32 fromLine = OffsetToLine(fromOffset);
  42         int32 toLine = OffsetToLine(toOffset);
  43
  44         int32 count = toLine - fromLine;
  45         if (count > 0)
  46                 RemoveLines(fromLine + 1, count);
  47
  48         BumpOffset(fromOffset - toOffset, fromLine + 1);
  49 }
  50
  51
  52 int32
  53 BTextView::LineBuffer::OffsetToLine(int32 offset) const
  54 {
  55         int32 minIndex = 0;
  56         int32 maxIndex = fItemCount - 1;
  57         int32 index = 0;
  58
  59         while (minIndex < maxIndex) {
  60                 index = (minIndex + maxIndex) >> 1;
  61                 if (offset >= fBuffer[index].offset) {
  62                         if (offset < fBuffer[index + 1].offset)
  63                                 break;
  64                         else
  65                                 minIndex = index + 1;
  66                 } else
  67                         maxIndex = index;
  68         }
  69
  70         return index;
  71 }
  72
  73
  74 int32
  75 BTextView::LineBuffer::PixelToLine(float pixel) const
  76 {
  77         int32 minIndex = 0;
  78         int32 maxIndex = fItemCount - 1;
  79         int32 index = 0;
  80
  81         while (minIndex < maxIndex) {
  82                 index = (minIndex + maxIndex) >> 1;
  83                 if (pixel >= fBuffer[index].origin) {
  84                         if (pixel < fBuffer[index + 1].origin)
  85                                 break;
  86                         else
  87                                 minIndex = index + 1;
  88                 } else
  89                         maxIndex = index;
  90         }
  91
  92         return index;
  93 }
  94
  95
  96 void
  97 BTextView::LineBuffer::BumpOrigin(float delta, int32 index)
  98 {
  99         for (long i = index; i < fItemCount; i++)
 100                 fBuffer[i].origin += delta;
 101 }
 102
 103
 104 void
 105 BTextView::LineBuffer::BumpOffset(int32 delta, int32 index)
 106 {
 107         for (long i = index; i < fItemCount; i++)
 108                 fBuffer[i].offset += delta;
 109 }
 110
 111
 112 float
 113 BTextView::LineBuffer::MaxWidth() const
 114 {
 115         if (fItemCount == 0)
 116                 return 0;
 117
 118         float maxWidth = 0;
 119         STELine* line = &fBuffer[0];
 120         for (int32 i = 0; i < fItemCount; i++) {
 121                 if (maxWidth < line->width)
 122                         maxWidth = line->width;
 123                 line++;
 124         }
 125         return maxWidth;
 126 }