[lua] Add fillText() and measureText() functions to GraphicsContext

src/app/script/canvas_widget.cpp

@@ -43,6 +43,7 @@ void Canvas::callPaint()
 
   // Draw only on resize (onPaint we draw the cached m_surface)
   GraphicsContext gc(m_surface);
+  gc.font(AddRef(font()));
   Paint(gc);
 }
 

src/app/script/graphics_context.cpp

@@ -16,12 +16,25 @@
 #include "app/script/engine.h"
 #include "app/script/luacpp.h"
 #include "app/util/conversion_to_surface.h"
+#include "os/draw_text.h"
 
 #ifdef ENABLE_UI
 
 namespace app {
 namespace script {
 
+void GraphicsContext::fillText(const std::string& text, int x, int y)
+{
+  os::draw_text(m_surface.get(), m_font.get(),
+                text, m_paint.color(), 0, x, y, nullptr);
+}
+
+gfx::Size GraphicsContext::measureText(const std::string& text) const
+{
+  return os::draw_text(nullptr, m_font.get(), text,
+                       0, 0, 0, 0, nullptr).size();
+}
+
 void GraphicsContext::drawImage(const doc::Image* img, int x, int y)
 {
   convert_image_to_surface(
@@ -72,6 +85,27 @@ int GraphicsContext_fillRect(lua_State* L)
   return 0;
 }
 
+int GraphicsContext_fillText(lua_State* L)
+{
+  auto gc = get_obj<GraphicsContext>(L, 1);
+  if (const char* text = lua_tostring(L, 2)) {
+    int x = lua_tointeger(L, 3);
+    int y = lua_tointeger(L, 4);
+    gc->fillText(text, x, y);
+  }
+  return 0;
+}
+
+int GraphicsContext_measureText(lua_State* L)
+{
+  auto gc = get_obj<GraphicsContext>(L, 1);
+  if (const char* text = lua_tostring(L, 2)) {
+    push_obj(L, gc->measureText(text));
+    return 1;
+  }
+  return 0;
+}
+
 int GraphicsContext_drawImage(lua_State* L)
 {
   auto gc = get_obj<GraphicsContext>(L, 1);
@@ -148,6 +182,8 @@ const luaL_Reg GraphicsContext_methods[] = {
   { "restore", GraphicsContext_restore },
   { "strokeRect", GraphicsContext_strokeRect },
   { "fillRect", GraphicsContext_fillRect },
+  { "fillText", GraphicsContext_fillText },
+  { "measureText", GraphicsContext_measureText },
   { "drawImage", GraphicsContext_drawImage },
   { nullptr, nullptr }
 };

src/app/script/graphics_context.h

@@ -10,6 +10,7 @@
 
 #ifdef ENABLE_UI
 
+#include "os/font.h"
 #include "os/paint.h"
 #include "os/surface.h"
 
@@ -27,8 +28,13 @@ public:
   GraphicsContext(const os::SurfaceRef& surface) : m_surface(surface) { }
   GraphicsContext(GraphicsContext&& gc) {
     std::swap(m_surface, gc.m_surface);
+    std::swap(m_paint, gc.m_paint);
+    std::swap(m_font, gc.m_font);
   }
 
+  os::FontRef font() const { return m_font; }
+  void font(const os::FontRef& font) { m_font = font; }
+
   int width() const { return m_surface->width(); }
   int height() const { return m_surface->height(); }
 
@@ -45,6 +51,15 @@ public:
     }
   }
 
+  bool antialias() const { return m_paint.antialias(); }
+  void antialias(bool value) { m_paint.antialias(value); }
+
+  gfx::Color color() const { return m_paint.color(); }
+  void color(gfx::Color color) { m_paint.color(color); }
+
+  float strokeWidth() const { return m_paint.strokeWidth(); }
+  void strokeWidth(float value) { m_paint.strokeWidth(value); }
+
   void strokeRect(const gfx::Rect& rc) {
     m_paint.style(os::Paint::Stroke);
     m_surface->drawRect(rc, m_paint);
@@ -55,20 +70,15 @@ public:
     m_surface->drawRect(rc, m_paint);
   }
 
-  bool antialias() const { return m_paint.antialias(); }
-  void antialias(bool value) { m_paint.antialias(value); }
-
-  gfx::Color color() const { return m_paint.color(); }
-  void color(gfx::Color color) { m_paint.color(color); }
-
-  float strokeWidth() const { return m_paint.strokeWidth(); }
-  void strokeWidth(float value) { m_paint.strokeWidth(value); }
+  void fillText(const std::string& text, int x, int y);
+  gfx::Size measureText(const std::string& text) const;
 
   void drawImage(const doc::Image* img, int x, int y);
 
 private:
   os::SurfaceRef m_surface = nullptr;
   os::Paint m_paint;
+  os::FontRef m_font;
   std::stack<os::Paint> m_saved;
 };