grab from latest android
git-svn-id: http://skia.googlecode.com/svn/trunk@27 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/views/SkTextBox.cpp b/src/views/SkTextBox.cpp
new file mode 100644
index 0000000..657f648
--- /dev/null
+++ b/src/views/SkTextBox.cpp
@@ -0,0 +1,216 @@
+/* libs/graphics/views/SkTextBox.cpp
+**
+** Copyright 2006, The Android Open Source Project
+**
+** Licensed under the Apache License, Version 2.0 (the "License");
+** you may not use this file except in compliance with the License.
+** You may obtain a copy of the License at
+**
+** http://www.apache.org/licenses/LICENSE-2.0
+**
+** Unless required by applicable law or agreed to in writing, software
+** distributed under the License is distributed on an "AS IS" BASIS,
+** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+** See the License for the specific language governing permissions and
+** limitations under the License.
+*/
+
+#include "SkTextBox.h"
+#include "SkGlyphCache.h"
+#include "SkUtils.h"
+#include "SkAutoKern.h"
+
+static inline int is_ws(int c)
+{
+ return !((c - 1) >> 5);
+}
+
+static size_t linebreak(const char text[], const char stop[], const SkPaint& paint, SkScalar margin)
+{
+ const char* start = text;
+
+ SkAutoGlyphCache ac(paint, NULL);
+ SkGlyphCache* cache = ac.getCache();
+ SkFixed w = 0;
+ SkFixed limit = SkScalarToFixed(margin);
+ SkAutoKern autokern;
+
+ const char* word_start = text;
+ int prevWS = true;
+
+ while (text < stop)
+ {
+ const char* prevText = text;
+ SkUnichar uni = SkUTF8_NextUnichar(&text);
+ int currWS = is_ws(uni);
+ const SkGlyph& glyph = cache->getUnicharMetrics(uni);
+
+ if (!currWS && prevWS)
+ word_start = prevText;
+ prevWS = currWS;
+
+ w += autokern.adjust(glyph) + glyph.fAdvanceX;
+ if (w > limit)
+ {
+ if (currWS) // eat the rest of the whitespace
+ {
+ while (text < stop && is_ws(SkUTF8_ToUnichar(text)))
+ text += SkUTF8_CountUTF8Bytes(text);
+ }
+ else // backup until a whitespace (or 1 char)
+ {
+ if (word_start == start)
+ {
+ if (prevText > start)
+ text = prevText;
+ }
+ else
+ text = word_start;
+ }
+ break;
+ }
+ }
+ return text - start;
+}
+
+int SkTextLineBreaker::CountLines(const char text[], size_t len, const SkPaint& paint, SkScalar width)
+{
+ const char* stop = text + len;
+ int count = 0;
+
+ if (width > 0)
+ {
+ do {
+ count += 1;
+ text += linebreak(text, stop, paint, width);
+ } while (text < stop);
+ }
+ return count;
+}
+
+//////////////////////////////////////////////////////////////////////////////
+
+SkTextBox::SkTextBox()
+{
+ fBox.setEmpty();
+ fSpacingMul = SK_Scalar1;
+ fSpacingAdd = 0;
+ fMode = kLineBreak_Mode;
+ fSpacingAlign = kStart_SpacingAlign;
+}
+
+void SkTextBox::setMode(Mode mode)
+{
+ SkASSERT((unsigned)mode < kModeCount);
+ fMode = SkToU8(mode);
+}
+
+void SkTextBox::setSpacingAlign(SpacingAlign align)
+{
+ SkASSERT((unsigned)align < kSpacingAlignCount);
+ fSpacingAlign = SkToU8(align);
+}
+
+void SkTextBox::getBox(SkRect* box) const
+{
+ if (box)
+ *box = fBox;
+}
+
+void SkTextBox::setBox(const SkRect& box)
+{
+ fBox = box;
+}
+
+void SkTextBox::setBox(SkScalar left, SkScalar top, SkScalar right, SkScalar bottom)
+{
+ fBox.set(left, top, right, bottom);
+}
+
+void SkTextBox::getSpacing(SkScalar* mul, SkScalar* add) const
+{
+ if (mul)
+ *mul = fSpacingMul;
+ if (add)
+ *add = fSpacingAdd;
+}
+
+void SkTextBox::setSpacing(SkScalar mul, SkScalar add)
+{
+ fSpacingMul = mul;
+ fSpacingAdd = add;
+}
+
+/////////////////////////////////////////////////////////////////////////////////////////////
+
+void SkTextBox::draw(SkCanvas* canvas, const char text[], size_t len, const SkPaint& paint)
+{
+ SkASSERT(canvas && &paint && (text || len == 0));
+
+ SkScalar marginWidth = fBox.width();
+
+ if (marginWidth <= 0 || len == 0)
+ return;
+
+ const char* textStop = text + len;
+
+ SkScalar x, y, scaledSpacing, height, fontHeight;
+ SkPaint::FontMetrics metrics;
+
+ switch (paint.getTextAlign()) {
+ case SkPaint::kLeft_Align:
+ x = 0;
+ break;
+ case SkPaint::kCenter_Align:
+ x = SkScalarHalf(marginWidth);
+ break;
+ default:
+ x = marginWidth;
+ break;
+ }
+ x += fBox.fLeft;
+
+ fontHeight = paint.getFontMetrics(&metrics);
+ scaledSpacing = SkScalarMul(fontHeight, fSpacingMul) + fSpacingAdd;
+ height = fBox.height();
+
+ // compute Y position for first line
+ {
+ SkScalar textHeight = fontHeight;
+
+ if (fMode == kLineBreak_Mode && fSpacingAlign != kStart_SpacingAlign)
+ {
+ int count = SkTextLineBreaker::CountLines(text, textStop - text, paint, marginWidth);
+ SkASSERT(count > 0);
+ textHeight += scaledSpacing * (count - 1);
+ }
+
+ switch (fSpacingAlign) {
+ case kStart_SpacingAlign:
+ y = 0;
+ break;
+ case kCenter_SpacingAlign:
+ y = SkScalarHalf(height - textHeight);
+ break;
+ default:
+ SkASSERT(fSpacingAlign == kEnd_SpacingAlign);
+ y = height - textHeight;
+ break;
+ }
+ y += fBox.fTop - metrics.fAscent;
+ }
+
+ for (;;)
+ {
+ len = linebreak(text, textStop, paint, marginWidth);
+ if (y + metrics.fDescent + metrics.fLeading > 0)
+ canvas->drawText(text, len, x, y, paint);
+ text += len;
+ if (text >= textStop)
+ break;
+ y += scaledSpacing;
+ if (y + metrics.fAscent >= height)
+ break;
+ }
+}
+