SampleTextAlpha.cpp revision e9d1b299ccbf8017ba57040986ded638f954684a 
1/*
2 * Copyright 2011 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#include "SampleCode.h"
8#include "SkBlurMask.h"
9#include "SkBlurMaskFilter.h"
10#include "SkCanvas.h"
11#include "SkGradientShader.h"
12#include "SkGraphics.h"
13#include "SkPath.h"
14#include "SkRandom.h"
15#include "SkRegion.h"
16#include "SkShader.h"
17#include "SkUtils.h"
18#include "SkXfermode.h"
19#include "SkColorPriv.h"
20#include "SkColorFilter.h"
21#include "SkTime.h"
22#include "SkTypeface.h"
23#include "SkView.h"
24
25#include "SkOSFile.h"
26#include "SkStream.h"
27
28class TextAlphaView : public SampleView {
29public:
30    TextAlphaView() {
31        fByte = 0xFF;
32    }
33
34protected:
35    // overrides from SkEventSink
36    bool onQuery(SkEvent* evt) override {
37        if (SampleCode::TitleQ(*evt)) {
38            SampleCode::TitleR(evt, "TextAlpha");
39            return true;
40        }
41        return this->INHERITED::onQuery(evt);
42    }
43
44    void onDrawContent(SkCanvas* canvas) override {
45        const char* str = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
46        SkPaint paint;
47        SkScalar    x = SkIntToScalar(10);
48        SkScalar    y = SkIntToScalar(20);
49
50        paint.setFlags(0x105);
51
52        paint.setARGB(fByte, 0xFF, 0xFF, 0xFF);
53
54        paint.setMaskFilter(SkBlurMaskFilter::Make(kNormal_SkBlurStyle,
55                                                   SkBlurMask::ConvertRadiusToSigma(3)));
56
57        SkRandom rand;
58
59        for (int ps = 6; ps <= 35; ps++) {
60            paint.setColor(rand.nextU() | (0xFF << 24));
61            paint.setTextSize(SkIntToScalar(ps));
62            paint.setTextSize(SkIntToScalar(24));
63            canvas->drawText(str, strlen(str), x, y, paint);
64            y += paint.getFontMetrics(nullptr);
65        }
66    }
67
68    SkView::Click* onFindClickHandler(SkScalar x, SkScalar y, unsigned) override {
69        return new Click(this);
70    }
71
72    bool onClick(Click* click) override {
73        int y = click->fICurr.fY;
74        if (y < 0) {
75            y = 0;
76        } else if (y > 255) {
77            y = 255;
78        }
79        fByte = y;
80        this->inval(nullptr);
81        return true;
82    }
83
84private:
85    int fByte;
86
87    typedef SampleView INHERITED;
88};
89
90//////////////////////////////////////////////////////////////////////////////
91
92static SkView* MyFactory() { return new TextAlphaView; }
93static SkViewRegister reg(MyFactory);
94