Merge branch 'textAlign'

lib/canvas.js

@@ -500,4 +500,40 @@ Context2d.prototype.__defineSetter__('font', function(val){
 
 Context2d.prototype.__defineGetter__('font', function(){
   return this.lastFontString || '10px sans-serif';
+});
+
+/**
+ * Set text alignment.
+ *
+ * @api public
+ */
+
+Context2d.prototype.__defineSetter__('textAlign', function(val){
+  switch (val) {
+    case 'center':
+      this.setTextAlignment(0);
+      this.lastTextAlignment = val;
+      break;
+    case 'left':
+    case 'start':
+      this.setTextAlignment(-1);
+      this.lastTextAlignment = val;
+      break;
+    case 'right':
+    case 'end':
+      this.setTextAlignment(1);
+      this.lastTextAlignment = val;
+      break;
+  }
+});
+
+/**
+ * Get the current font.
+ *
+ * @see exports.parseFont()
+ * @api public
+ */
+
+Context2d.prototype.__defineGetter__('textAlign', function(){
+  return this.lastTextAlignment || 'start';
 });

src/CanvasRenderingContext2d.cc

@@ -88,6 +88,7 @@ Context2d::Initialize(Handle<Object> target) {
   NODE_SET_PROTOTYPE_METHOD(t, "strokeRect", StrokeRect);
   NODE_SET_PROTOTYPE_METHOD(t, "clearRect", ClearRect);
   NODE_SET_PROTOTYPE_METHOD(t, "rect", Rect);
+  NODE_SET_PROTOTYPE_METHOD(t, "setTextAlignment", SetTextAlignment);
   NODE_SET_PROTOTYPE_METHOD(t, "setTextPath", SetTextPath);
   NODE_SET_PROTOTYPE_METHOD(t, "measureText", MeasureText);
   NODE_SET_PROTOTYPE_METHOD(t, "moveTo", MoveTo);
@@ -139,6 +140,7 @@ Context2d::Context2d(Canvas *canvas): ObjectWrap() {
   shadowBlur = shadowOffsetX = shadowOffsetY = 0;
   state = states[stateno = 0] = (canvas_state_t *) malloc(sizeof(canvas_state_t));
   state->globalAlpha = 1;
+  state->textAlignment = -1;
   state->fillPattern = state->strokePattern = NULL;
   RGBA(state->fill,0,0,0,1);
   RGBA(state->stroke,0,0,0,1);
@@ -866,6 +868,22 @@ Context2d::MeasureText(const Arguments &args) {
   return scope.Close(obj);
 }
 
+/*
+ * Set text alignment. -1 0 1
+ */
+
+Handle<Value>
+Context2d::SetTextAlignment(const Arguments &args) {
+  HandleScope scope;
+
+  if (!args[0]->IsInt32()) return Undefined();
+  Context2d *context = ObjectWrap::Unwrap<Context2d>(args.This());
+  context->state->textAlignment = args[0]->Int32Value();
+
+  return Undefined();
+}
+
+
 /*
  * Set text path at x, y.
  */
@@ -886,7 +904,23 @@ Context2d::SetTextPath(const Arguments &args) {
 
   Context2d *context = ObjectWrap::Unwrap<Context2d>(args.This());
   cairo_t *ctx = context->getContext();
+
+  // Text extents
   cairo_text_extents_t te;
+  cairo_text_extents(ctx, *str, &te);
+
+  // Alignment
+  switch (context->state->textAlignment) {
+    // center
+    case 0:
+      x -= te.width / 2 + te.x_bearing;
+      break;
+    // right
+    case 1:
+      x -= te.width + te.x_bearing;
+      break;
+  }
+
   cairo_move_to(ctx, x, y);
   cairo_text_path(ctx, *str);
 

src/CanvasRenderingContext2d.h

@@ -32,6 +32,7 @@ typedef struct {
   cairo_pattern_t *fillPattern;
   cairo_pattern_t *strokePattern;
   float globalAlpha;
+  short textAlignment;
 } canvas_state_t;
 
 class Context2d: public node::ObjectWrap {
@@ -64,6 +65,7 @@ class Context2d: public node::ObjectWrap {
     static Handle<Value> SetShadowRGBA(const Arguments &args);
     static Handle<Value> SetFillPattern(const Arguments &args);
     static Handle<Value> SetStrokePattern(const Arguments &args);
+    static Handle<Value> SetTextAlignment(const Arguments &args);
     static Handle<Value> SetTextPath(const Arguments &args);
     static Handle<Value> MeasureText(const Arguments &args);
     static Handle<Value> BezierCurveTo(const Arguments &args);

test/canvas.test.js

@@ -747,6 +747,99 @@ module.exports = {
       , 'Context2d#strokeText()');    
   },
   
+  'test Context2d#textAlign': function(assert){
+    var canvas = new Canvas(200,200)
+      , ctx = canvas.getContext('2d');
+
+    assert.equal('start', ctx.textAlign);
+    ctx.textAlign = 'center';
+    assert.equal('center', ctx.textAlign);
+    ctx.textAlign = 'right';
+    assert.equal('right', ctx.textAlign);
+    ctx.textAlign = 'end';
+    assert.equal('end', ctx.textAlign);
+    ctx.textAlign = 'fail';
+    assert.equal('end', ctx.textAlign);
+  },
+  
+  'test Context2d#textAlign= right': function(assert){
+    var canvas = new Canvas(200, 200)
+      , ctx = canvas.getContext('2d')
+      , path = __dirname + '/images/textAlign-right.png';
+
+    ctx.strokeRect(0,0,200,200);
+    ctx.lineTo(0,100);
+    ctx.lineTo(200,100);
+    ctx.stroke();
+
+    ctx.beginPath();
+    ctx.lineTo(100,0);
+    ctx.lineTo(100,200);
+    ctx.stroke();
+
+    ctx.font = 'normal 20px Arial';
+    ctx.textAlign = 'right';
+    ctx.fillText("Wahoo", 100, 100);
+    
+    assertChecksum(
+        canvas
+      , path
+      , 'cde33254c5c6de39e1a549edcb23d93e'
+      , 'Context2d#textAlign= right failed');
+  },
+  
+  'test Context2d#textAlign= center': function(assert){
+    var canvas = new Canvas(200, 200)
+      , ctx = canvas.getContext('2d')
+      , path = __dirname + '/images/textAlign-center.png';
+
+    ctx.strokeRect(0,0,200,200);
+    ctx.lineTo(0,100);
+    ctx.lineTo(200,100);
+    ctx.stroke();
+
+    ctx.beginPath();
+    ctx.lineTo(100,0);
+    ctx.lineTo(100,200);
+    ctx.stroke();
+
+    ctx.font = 'normal 20px Arial';
+    ctx.textAlign = 'center';
+    ctx.fillText("Wahoo", 100, 100);
+    
+    assertChecksum(
+        canvas
+      , path
+      , '31b217e572ce2d78f11c1ecf21713579'
+      , 'Context2d#textAlign= center failed');
+  },
+  
+  'test Context2d#textAlign= left': function(assert){
+    var canvas = new Canvas(200, 200)
+      , ctx = canvas.getContext('2d')
+      , path = __dirname + '/images/textAlign-left.png';
+
+    ctx.strokeRect(0,0,200,200);
+    ctx.lineTo(0,100);
+    ctx.lineTo(200,100);
+    ctx.stroke();
+
+    ctx.beginPath();
+    ctx.lineTo(100,0);
+    ctx.lineTo(100,200);
+    ctx.stroke();
+
+    ctx.font = 'normal 20px Arial';
+    ctx.textAlign = 'left';
+    ctx.fillText("Wahoo", 100, 100);
+    
+    assertChecksum(
+        canvas
+      , path
+      , 'f22146910b2df4b96550611f45dda77a'
+      , 'Context2d#textAlign= left failed');
+  },
+  
   'test Context2d#measureText()': function(assert){
     var canvas = new Canvas(200, 200)
       , ctx = canvas.getContext('2d');