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      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 
     13 extern "C" {
     14 #include "lua.h"
     15 #include "lualib.h"
     16 #include "lauxlib.h"
     17 }
     18 
     19 static const char gDrawName[] = "onDrawContent";
     20 
     21 static const char gCode[] = ""
     22     "require \"math\" "
     23     ""
     24     "local r = { left = 10, top = 10, right = 100, bottom = 80 } "
     25     "local x = 0;"
     26     ""
     27     "local paint = Sk.newPaint();"
     28     "paint:setAntiAlias(true);"
     29     ""
     30     "local image = Sk.loadImage('/skia/trunk/sailboat.jpg');"
     31     ""
     32     "local color = {a = 1, r = 1, g = 0, b = 0};"
     33     ""
     34     "function rnd(range) "
     35     "   return math.random() * range;"
     36     "end "
     37     ""
     38     "rndX = function () return rnd(640) end "
     39     "rndY = function () return rnd(480) end "
     40     ""
     41     "function draw_rand_path(canvas);"
     42     "   if not path_paint then "
     43     "       path_paint = Sk.newPaint();"
     44     "       path_paint:setAntiAlias(true);"
     45     "   end "
     46     "   path_paint:setColor({a = 1, r = math.random(), g = math.random(), b = math.random() });"
     47     ""
     48     "   local path = Sk.newPath();"
     49     "   path:moveTo(rndX(), rndY());"
     50     "   for i = 0, 50 do "
     51     "       path:quadTo(rndX(), rndY(), rndX(), rndY());"
     52     "   end "
     53     "   canvas:drawPath(path, path_paint);"
     54     ""
     55     "   paint:setColor{a=1,r=0,g=0,b=1};"
     56     "   local align = { 'left', 'center', 'right' };"
     57     "   paint:setTextSize(30);"
     58     "   for k, v in next, align do "
     59     "       paint:setTextAlign(v);"
     60     "       canvas:drawText('Hamburgefons', 320, 200 + 30*k, paint);"
     61     "   end "
     62     "end "
     63     ""
     64     "function onStartup() "
     65     "   local paint = Sk.newPaint();"
     66     "   paint:setColor{a=1, r=1, g=0, b=0};"
     67     "   local doc = Sk.newDocumentPDF('/skia/trunk/test.pdf');"
     68     "   local canvas = doc:beginPage(72*8.5, 72*11);"
     69     "   canvas:drawText('Hello Lua', 300, 300, paint);"
     70     "   doc:close();"
     71     "   doc = nil;"
     72     "end "
     73     ""
     74     "function onDrawContent(canvas) "
     75     "   draw_rand_path(canvas);"
     76     "   color.g = x / 100;"
     77     "   paint:setColor(color) "
     78     "   canvas:translate(x, 0);"
     79     "   canvas:drawOval(r, paint) "
     80     "   x = x + 1;"
     81     "   canvas:drawImage(image, x, r.bottom + 50, 0.5);"
     82     "   if x > 100 then x = 0 end;"
     83     "end "
     84     ""
     85     "onStartup();";
     86 
     87 class LuaView : public SampleView {
     88 public:
     89     LuaView() : fLua(NULL) {}
     90 
     91     virtual ~LuaView() {
     92         SkDELETE(fLua);
     93     }
     94 
     95     lua_State* ensureLua() {
     96         if (NULL == fLua) {
     97             fLua = SkNEW(SkLua);
     98             fLua->runCode(gCode);
     99         }
    100         return fLua->get();
    101     }
    102 
    103 protected:
    104     virtual bool onQuery(SkEvent* evt) SK_OVERRIDE {
    105         if (SampleCode::TitleQ(*evt)) {
    106             SampleCode::TitleR(evt, "Lua");
    107             return true;
    108         }
    109         SkUnichar uni;
    110         if (SampleCode::CharQ(*evt, &uni)) {
    111         }
    112         return this->INHERITED::onQuery(evt);
    113     }
    114 
    115     virtual void onDrawContent(SkCanvas* canvas) SK_OVERRIDE {
    116         lua_State* L = this->ensureLua();
    117 
    118         lua_getglobal(L, gDrawName);
    119         if (!lua_isfunction(L, -1)) {
    120             int t = lua_type(L, -1);
    121             SkDebugf("--- expected %s function %d, ignoring.\n", gDrawName, t);
    122             lua_pop(L, 1);
    123         } else {
    124             // does it make sense to try to "cache" the lua version of this
    125             // canvas between draws?
    126             fLua->pushCanvas(canvas);
    127             if (lua_pcall(L, 1, 0, 0) != LUA_OK) {
    128                 SkDebugf("lua err: %s\n", lua_tostring(L, -1));
    129             }
    130         }
    131         // need a way for the lua-sample to tell us if they want animations...
    132         // hard-code it ON for now.
    133         this->inval(NULL);
    134     }
    135 
    136     virtual SkView::Click* onFindClickHandler(SkScalar x, SkScalar y,
    137                                               unsigned modi) SK_OVERRIDE {
    138         return this->INHERITED::onFindClickHandler(x, y, modi);
    139     }
    140 
    141     virtual bool onClick(Click* click) SK_OVERRIDE {
    142         return this->INHERITED::onClick(click);
    143     }
    144 
    145 private:
    146     SkLua* fLua;
    147 
    148     typedef SampleView INHERITED;
    149 };
    150 
    151 //////////////////////////////////////////////////////////////////////////////
    152 
    153 static SkView* MyFactory() { return new LuaView; }
    154 static SkViewRegister reg(MyFactory);
    155