SampleMeasure.cpp revision ec3ed6a5ebf6f2c406d7bcf94b6bc34fcaeb976e 
1
2/*
3 * Copyright 2011 Google Inc.
4 *
5 * Use of this source code is governed by a BSD-style license that can be
6 * found in the LICENSE file.
7 */
8#include "SampleCode.h"
9#include "SkView.h"
10#include "SkCanvas.h"
11#include "SkGradientShader.h"
12#include "SkPath.h"
13#include "SkRegion.h"
14#include "SkShader.h"
15#include "SkUtils.h"
16#include "Sk1DPathEffect.h"
17#include "SkCornerPathEffect.h"
18#include "SkPathMeasure.h"
19#include "SkRandom.h"
20#include "SkColorPriv.h"
21#include "SkColorFilter.h"
22#include "SkDither.h"
23
24// exercise scale/linear/devkern
25struct Setting {
26    SkScalar    fScale;
27    bool        fLinearText;
28    bool        fDevKernText;
29};
30
31static const SkScalar ONE = SkIntToScalar(9999)/10000;
32
33static const Setting gSettings[] = {
34    { 0,            false,  false   },
35    { 0,            false,  true    },
36    { 0,            true,   false   },
37    { 0,            true,   true    },
38    { ONE,   false,  false   },
39    { ONE,   false,  true    },
40    { ONE,   true,   false   },
41    { ONE,   true,   true    }
42};
43
44static void doMeasure(SkCanvas* canvas, const SkPaint& paint, const char text[]) {
45    SkScalar    dy = paint.getFontMetrics(NULL);
46
47    size_t      len = strlen(text);
48    SkAutoTMalloc<SkScalar> autoWidths(len);
49    SkScalar*   widths = autoWidths.get();
50    SkAutoTMalloc<SkRect> autoRects(len);
51    SkRect*     rects = autoRects.get();
52    SkRect      bounds;
53
54    SkPaint p(paint);
55    for (size_t i = 0; i < SK_ARRAY_COUNT(gSettings); i++) {
56        p.setLinearText(gSettings[i].fLinearText);
57        p.setDevKernText(gSettings[i].fDevKernText);
58        SkScalar scale = gSettings[i].fScale;
59
60        int n = p.getTextWidths(text, len, widths, rects);
61        SkScalar w = p.measureText(text, len, &bounds, scale);
62
63        p.setStyle(SkPaint::kFill_Style);
64        p.setColor(0x8888FF88);
65        canvas->drawRect(bounds, p);
66        p.setColor(0xFF000000);
67        canvas->drawText(text, len, 0, 0, p);
68
69        p.setStyle(SkPaint::kStroke_Style);
70        p.setStrokeWidth(0);
71        p.setColor(0xFFFF0000);
72        SkScalar x = 0;
73        for (int j = 0; j < n; j++) {
74            SkRect r = rects[j];
75            r.offset(x, 0);
76            canvas->drawRect(r, p);
77            x += widths[j];
78        }
79
80        p.setColor(0xFF0000FF);
81        canvas->drawLine(0, 0, w, 0, p);
82        p.setStrokeWidth(SkIntToScalar(4));
83        canvas->drawPoint(x, 0, p);
84
85        canvas->translate(0, dy);
86    }
87}
88
89class MeasureView : public SampleView {
90public:
91    SkPaint fPaint;
92
93	MeasureView() {
94        fPaint.setAntiAlias(true);
95        fPaint.setTextSize(SkIntToScalar(64));
96        this->setBGColor(0xFFDDDDDD);
97    }
98
99protected:
100    // overrides from SkEventSink
101    virtual bool onQuery(SkEvent* evt) {
102        if (SampleCode::TitleQ(*evt)) {
103            SampleCode::TitleR(evt, "Measure");
104            return true;
105        }
106        return this->INHERITED::onQuery(evt);
107    }
108
109    virtual void onDrawContent(SkCanvas* canvas) {
110        canvas->translate(fPaint.getTextSize(), fPaint.getTextSize());
111        doMeasure(canvas, fPaint, "Hamburgefons");
112    }
113
114private:
115    typedef SampleView INHERITED;
116};
117
118//////////////////////////////////////////////////////////////////////////////
119
120static SkView* MyFactory() { return new MeasureView; }
121static SkViewRegister reg(MyFactory);
122
123