1 /*
2 * Copyright 2013 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 "SampleCode.h"
9 #include "SkView.h"
10 #include "SkLua.h"
11 #include "SkCanvas.h"
12 #include "Resources.h"
13 #include "SkData.h"
14
15 extern "C" {
16 #include "lua.h"
17 #include "lualib.h"
18 #include "lauxlib.h"
19 }
20
21 //#define LUA_FILENAME "test.lua"
22 #define LUA_FILENAME "slides.lua"
23
24 static const char gDrawName[] = "onDrawContent";
25 static const char gClickName[] = "onClickHandler";
26 static const char gUnicharName[] = "onCharHandler";
27
28 static const char gLuaClickHandlerName[] = "lua-click-handler";
29
30 static const char gMissingCode[] = ""
31 "local paint = Sk.newPaint()"
32 "paint:setAntiAlias(true)"
33 "paint:setTextSize(30)"
34 ""
35 "function onDrawContent(canvas)"
36 " canvas:drawText('missing \"test.lua\"', 20, 50, paint)"
37 "end"
38 ;
39
40 class LuaView : public SampleView {
41 public:
LuaView()42 LuaView() : fLua(nullptr) {}
43
~LuaView()44 virtual ~LuaView() { delete fLua; }
45
setImageFilename(lua_State * L)46 void setImageFilename(lua_State* L) {
47 SkString str = GetResourcePath("mandrill_256.png");
48
49 lua_getglobal(L, "setImageFilename");
50 if (lua_isfunction(L, -1)) {
51 fLua->pushString(str.c_str());
52 if (lua_pcall(L, 1, 0, 0) != LUA_OK) {
53 SkDebugf("lua err: %s\n", lua_tostring(L, -1));
54 }
55 }
56 }
57
ensureLua()58 lua_State* ensureLua() {
59 if (nullptr == fLua) {
60 fLua = new SkLua;
61
62 SkString str = GetResourcePath(LUA_FILENAME);
63 sk_sp<SkData> data(SkData::MakeFromFileName(str.c_str()));
64 if (data) {
65 fLua->runCode(data->data(), data->size());
66 this->setImageFilename(fLua->get());
67 } else {
68 fLua->runCode(gMissingCode);
69 }
70 }
71 return fLua->get();
72 }
73
74 protected:
onQuery(SkEvent * evt)75 bool onQuery(SkEvent* evt) override {
76 if (SampleCode::TitleQ(*evt)) {
77 SampleCode::TitleR(evt, "Lua");
78 return true;
79 }
80 SkUnichar uni;
81 if (SampleCode::CharQ(*evt, &uni)) {
82 lua_State* L = this->ensureLua();
83 lua_getglobal(L, gUnicharName);
84 if (lua_isfunction(L, -1)) {
85 SkString str;
86 str.appendUnichar(uni);
87 fLua->pushString(str.c_str());
88 if (lua_pcall(L, 1, 1, 0) != LUA_OK) {
89 SkDebugf("lua err: %s\n", lua_tostring(L, -1));
90 } else {
91 if (lua_isboolean(L, -1) && lua_toboolean(L, -1)) {
92 this->inval(nullptr);
93 return true;
94 }
95 }
96 }
97 }
98 return this->INHERITED::onQuery(evt);
99 }
100
onDrawContent(SkCanvas * canvas)101 void onDrawContent(SkCanvas* canvas) override {
102 lua_State* L = this->ensureLua();
103
104 lua_getglobal(L, gDrawName);
105 if (!lua_isfunction(L, -1)) {
106 int t = lua_type(L, -1);
107 SkDebugf("--- expected %s function %d, ignoring.\n", gDrawName, t);
108 lua_pop(L, 1);
109 } else {
110 // does it make sense to try to "cache" the lua version of this
111 // canvas between draws?
112 fLua->pushCanvas(canvas);
113 fLua->pushScalar(this->width());
114 fLua->pushScalar(this->height());
115 if (lua_pcall(L, 3, 1, 0) != LUA_OK) {
116 SkDebugf("lua err: %s\n", lua_tostring(L, -1));
117 } else {
118 if (lua_isboolean(L, -1) && lua_toboolean(L, -1)) {
119 this->inval(nullptr);
120 }
121 }
122 }
123 }
124
onFindClickHandler(SkScalar x,SkScalar y,unsigned modi)125 virtual SkView::Click* onFindClickHandler(SkScalar x, SkScalar y,
126 unsigned modi) override {
127 lua_State* L = this->ensureLua();
128 lua_getglobal(L, gClickName);
129 if (lua_isfunction(L, -1)) {
130 fLua->pushScalar(x);
131 fLua->pushScalar(y);
132 fLua->pushString("down");
133 if (lua_pcall(L, 3, 1, 0) != LUA_OK) {
134 SkDebugf("lua err: %s\n", lua_tostring(L, -1));
135 } else {
136 if (lua_isboolean(L, -1) && lua_toboolean(L, -1)) {
137 this->inval(nullptr);
138 Click* c = new Click(this);
139 c->setType(gLuaClickHandlerName);
140 return c;
141 }
142 }
143 }
144 return this->INHERITED::onFindClickHandler(x, y, modi);
145 }
146
onClick(Click * click)147 bool onClick(Click* click) override {
148 if (click->getType() != gLuaClickHandlerName) {
149 return this->INHERITED::onClick(click);
150 }
151
152 const char* state = nullptr;
153 switch (click->fState) {
154 case Click::kMoved_State:
155 state = "moved";
156 break;
157 case Click::kUp_State:
158 state = "up";
159 break;
160 default:
161 break;
162 }
163 if (state) {
164 this->inval(nullptr);
165 lua_State* L = fLua->get();
166 lua_getglobal(L, gClickName);
167 fLua->pushScalar(click->fCurr.x());
168 fLua->pushScalar(click->fCurr.y());
169 fLua->pushString(state);
170 lua_pcall(L, 3, 1, 0);
171 return lua_isboolean(L, -1) && lua_toboolean(L, -1);
172 }
173 return true;
174 }
175
176 private:
177 SkLua* fLua;
178
179 typedef SampleView INHERITED;
180 };
181
182 //////////////////////////////////////////////////////////////////////////////
183
MyFactory()184 static SkView* MyFactory() { return new LuaView; }
185 static SkViewRegister reg(MyFactory);
186