skia2/samplecode/SampleTextBox.cpp
Florin Malita 9867f61160 SkShaper per-line callback
Tweak SkShaper to call out for each line, instead of bundling everything
as a text blob.

Change-Id: Ic522f88afcf31cefd873dc8b5cde1ac2e107c64f
Reviewed-on: https://skia-review.googlesource.com/c/176592
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Florin Malita <fmalita@chromium.org>
2018-12-12 17:54:12 +00:00

113 lines
3.5 KiB
C++

/*
* Copyright 2011 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "Sample.h"
#include "SkBlurMaskFilter.h"
#include "SkCanvas.h"
#include "SkColorFilter.h"
#include "SkColorPriv.h"
#include "SkColorShader.h"
#include "SkGradientShader.h"
#include "SkGraphics.h"
#include "SkOSFile.h"
#include "SkPath.h"
#include "SkRandom.h"
#include "SkRegion.h"
#include "SkShader.h"
#include "SkShaper.h"
#include "SkStream.h"
#include "SkTextBlob.h"
#include "SkTime.h"
#include "SkTypeface.h"
#include "SkUTF.h"
extern void skia_set_text_gamma(float blackGamma, float whiteGamma);
#if defined(SK_BUILD_FOR_WIN) && defined(SK_FONTHOST_WIN_GDI)
extern SkTypeface* SkCreateTypefaceFromLOGFONT(const LOGFONT&);
#endif
static const char gText[] =
"When in the Course of human events it becomes necessary for one people "
"to dissolve the political bands which have connected them with another "
"and to assume among the powers of the earth, the separate and equal "
"station to which the Laws of Nature and of Nature's God entitle them, "
"a decent respect to the opinions of mankind requires that they should "
"declare the causes which impel them to the separation.";
class TextBoxView : public Sample {
public:
TextBoxView() {
#if defined(SK_BUILD_FOR_WIN) && defined(SK_FONTHOST_WIN_GDI)
LOGFONT lf;
sk_bzero(&lf, sizeof(lf));
lf.lfHeight = 9;
SkTypeface* tf0 = SkCreateTypefaceFromLOGFONT(lf);
lf.lfHeight = 12;
SkTypeface* tf1 = SkCreateTypefaceFromLOGFONT(lf);
// we assert that different sizes should not affect which face we get
SkASSERT(tf0 == tf1);
tf0->unref();
tf1->unref();
#endif
}
protected:
bool onQuery(Sample::Event* evt) override {
if (Sample::TitleQ(*evt)) {
Sample::TitleR(evt, "TextBox");
return true;
}
return this->INHERITED::onQuery(evt);
}
void drawTest(SkCanvas* canvas, SkScalar w, SkScalar h, SkColor fg, SkColor bg) {
SkAutoCanvasRestore acr(canvas, true);
canvas->clipRect(SkRect::MakeWH(w, h));
canvas->drawColor(bg);
SkShaper shaper(nullptr);
SkScalar margin = 20;
SkPaint paint;
paint.setAntiAlias(true);
paint.setLCDRenderText(true);
paint.setColor(fg);
for (int i = 9; i < 24; i += 2) {
SkTextBlobBuilderLineHandler builder;
paint.setTextSize(SkIntToScalar(i));
SkFont font = SkFont::LEGACY_ExtractFromPaint(paint);
SkPoint end = shaper.shape(&builder, font, gText, strlen(gText), true,
{ margin, margin }, w - margin);
canvas->drawTextBlob(builder.makeBlob(), 0, 0, paint);
canvas->translate(0, end.y());
}
}
void onDrawContent(SkCanvas* canvas) override {
SkScalar width = this->width() / 3;
drawTest(canvas, width, this->height(), SK_ColorBLACK, SK_ColorWHITE);
canvas->translate(width, 0);
drawTest(canvas, width, this->height(), SK_ColorWHITE, SK_ColorBLACK);
canvas->translate(width, 0);
drawTest(canvas, width, this->height()/2, SK_ColorGRAY, SK_ColorWHITE);
canvas->translate(0, this->height()/2);
drawTest(canvas, width, this->height()/2, SK_ColorGRAY, SK_ColorBLACK);
}
private:
typedef Sample INHERITED;
};
//////////////////////////////////////////////////////////////////////////////
DEF_SAMPLE( return new TextBoxView(); )