Home | History | Annotate | Download | only in gm 
      1 /*
      2  * Copyright 2014 Google Inc.
      3  *
      4  * Use of this source code is governed by a BSD-style license that can be
      5  * found in the LICENSE file.
      6  */
      7 
      8 #include "gm.h"
      9 #include "SkCanvas.h"
     10 #include "SkGradientShader.h"
     11 
     12 /**
     13  * This test exercises drawPosTextH and drawPosText with every text align.
     14  */
     15 static const int kWidth = 480;
     16 static const int kHeight = 600;
     17 static const SkScalar kTextHeight = 64.0f;
     18 static const int kMaxStringLength = 12;
     19 
     20 namespace skiagm {
     21 
     22 class GlyphPosAlignGM : public GM {
     23 protected:
     24     virtual uint32_t onGetFlags() const SK_OVERRIDE {
     25         return kSkipTiled_Flag;
     26     }
     27 
     28     virtual SkString onShortName() SK_OVERRIDE {
     29         return SkString("glyph_pos_align");
     30     }
     31 
     32     virtual SkISize onISize() { return SkISize::Make(kWidth, kHeight); }
     33 
     34     virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
     35         canvas->clear(SK_ColorBLACK);
     36 
     37         SkPaint paint;
     38         paint.setTextSize(kTextHeight);
     39         paint.setFakeBoldText(true);
     40         const SkColor colors[] = { SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE };
     41         const SkPoint pts[] = {{0, 0}, {kWidth, kHeight}};
     42         SkAutoTUnref<SkShader> grad(SkGradientShader::CreateLinear(pts, colors, NULL,
     43                                                                    SK_ARRAY_COUNT(colors),
     44                                                                    SkShader::kMirror_TileMode));
     45         paint.setShader(grad);
     46 
     47 
     48         paint.setTextAlign(SkPaint::kRight_Align);
     49         drawTestCase(canvas, "Right Align", kTextHeight, paint);
     50 
     51         paint.setTextAlign(SkPaint::kCenter_Align);
     52         drawTestCase(canvas, "Center Align", 4 * kTextHeight, paint);
     53 
     54         paint.setTextAlign(SkPaint::kLeft_Align);
     55         drawTestCase(canvas, "Left Align", 7 * kTextHeight, paint);
     56     }
     57 
     58     void drawTestCase(SkCanvas* canvas, const char* text, SkScalar y, const SkPaint& paint) {
     59         SkScalar widths[kMaxStringLength];
     60         SkScalar posX[kMaxStringLength];
     61         SkPoint pos[kMaxStringLength];
     62         int length = strlen(text);
     63         SkASSERT(length <= kMaxStringLength);
     64 
     65         paint.getTextWidths(text, length, widths);
     66 
     67         float originX;
     68         switch (paint.getTextAlign()) {
     69             case SkPaint::kRight_Align: originX = 1; break;
     70             case SkPaint::kCenter_Align: originX = 0.5f; break;
     71             case SkPaint::kLeft_Align: originX = 0; break;
     72             default: SkFAIL("Invalid paint origin"); return;
     73         }
     74 
     75         float x = kTextHeight;
     76         for (int i = 0; i < length; ++i) {
     77             posX[i] = x + originX * widths[i];
     78             pos[i].set(posX[i], i ? pos[i - 1].y() + 3 : y + kTextHeight);
     79             x += widths[i];
     80         }
     81 
     82         canvas->drawPosTextH(text, length, posX, y, paint);
     83         canvas->drawPosText(text, length, pos, paint);
     84     }
     85 
     86 private:
     87 
     88     typedef GM INHERITED;
     89 };
     90 
     91 //////////////////////////////////////////////////////////////////////////////
     92 
     93 static GM* GlyphPosAlignFactory(void*) {
     94     return new GlyphPosAlignGM();
     95 }
     96 
     97 static GMRegistry reg(GlyphPosAlignFactory);
     98 
     99 }
    100