skia2/samplecode/SampleLua.cpp

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/*
* Copyright 2013 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SampleCode.h"
#include "SkView.h"
#include "SkLua.h"
#include "SkCanvas.h"
#include "Resources.h"
#include "SkData.h"
extern "C" {
#include "lua.h"
#include "lualib.h"
#include "lauxlib.h"
}
//#define LUA_FILENAME "lua/test.lua"
#define LUA_FILENAME "lua/slides.lua"
static const char gDrawName[] = "onDrawContent";
static const char gClickName[] = "onClickHandler";
static const char gUnicharName[] = "onCharHandler";
static const char gMissingCode[] = ""
"local paint = Sk.newPaint()"
"paint:setAntiAlias(true)"
"paint:setTextSize(30)"
""
"function onDrawContent(canvas)"
" canvas:drawText('missing \"test.lua\"', 20, 50, paint)"
"end"
;
class LuaView : public SampleView {
public:
LuaView() : fLua(nullptr) {}
~LuaView() override { delete fLua; }
void setImageFilename(lua_State* L) {
SkString str = GetResourcePath("images/mandrill_256.png");
lua_getglobal(L, "setImageFilename");
if (lua_isfunction(L, -1)) {
fLua->pushString(str.c_str());
if (lua_pcall(L, 1, 0, 0) != LUA_OK) {
SkDebugf("lua err: %s\n", lua_tostring(L, -1));
}
}
}
lua_State* ensureLua() {
if (nullptr == fLua) {
fLua = new SkLua;
SkString str = GetResourcePath(LUA_FILENAME);
sk_sp<SkData> data(SkData::MakeFromFileName(str.c_str()));
if (data) {
fLua->runCode(data->data(), data->size());
this->setImageFilename(fLua->get());
} else {
fLua->runCode(gMissingCode);
}
}
return fLua->get();
}
protected:
bool onQuery(SkEvent* evt) override {
if (SampleCode::TitleQ(*evt)) {
SampleCode::TitleR(evt, "Lua");
return true;
}
SkUnichar uni;
if (SampleCode::CharQ(*evt, &uni)) {
lua_State* L = this->ensureLua();
lua_getglobal(L, gUnicharName);
if (lua_isfunction(L, -1)) {
SkString str;
str.appendUnichar(uni);
fLua->pushString(str.c_str());
if (lua_pcall(L, 1, 1, 0) != LUA_OK) {
SkDebugf("lua err: %s\n", lua_tostring(L, -1));
} else {
if (lua_isboolean(L, -1) && lua_toboolean(L, -1)) {
return true;
}
}
}
}
return this->INHERITED::onQuery(evt);
}
void onDrawContent(SkCanvas* canvas) override {
lua_State* L = this->ensureLua();
lua_getglobal(L, gDrawName);
if (!lua_isfunction(L, -1)) {
int t = lua_type(L, -1);
SkDebugf("--- expected %s function %d, ignoring.\n", gDrawName, t);
lua_pop(L, 1);
} else {
// does it make sense to try to "cache" the lua version of this
// canvas between draws?
fLua->pushCanvas(canvas);
fLua->pushScalar(this->width());
fLua->pushScalar(this->height());
if (lua_pcall(L, 3, 1, 0) != LUA_OK) {
SkDebugf("lua err: %s\n", lua_tostring(L, -1));
}
}
}
virtual SkView::Click* onFindClickHandler(SkScalar x, SkScalar y,
unsigned modi) override {
lua_State* L = this->ensureLua();
lua_getglobal(L, gClickName);
if (lua_isfunction(L, -1)) {
fLua->pushScalar(x);
fLua->pushScalar(y);
fLua->pushString("down");
if (lua_pcall(L, 3, 1, 0) != LUA_OK) {
SkDebugf("lua err: %s\n", lua_tostring(L, -1));
} else {
if (lua_isboolean(L, -1) && lua_toboolean(L, -1)) {
return new Click(this);
}
}
}
return this->INHERITED::onFindClickHandler(x, y, modi);
}
bool onClick(Click* click) override {
const char* state = nullptr;
switch (click->fState) {
case Click::kMoved_State:
state = "moved";
break;
case Click::kUp_State:
state = "up";
break;
default:
break;
}
if (state) {
lua_State* L = fLua->get();
lua_getglobal(L, gClickName);
fLua->pushScalar(click->fCurr.x());
fLua->pushScalar(click->fCurr.y());
fLua->pushString(state);
lua_pcall(L, 3, 1, 0);
return lua_isboolean(L, -1) && lua_toboolean(L, -1);
}
return true;
}
private:
SkLua* fLua;
typedef SampleView INHERITED;
};
//////////////////////////////////////////////////////////////////////////////
static SkView* MyFactory() { return new LuaView; }
static SkViewRegister reg(MyFactory);