Remove CGContextRef field in QuartzTextLayout as it is only used in draw method

where it can easily be provided. Retaining a CGContextRef in QuartzTextLayout
could lead to it being used after being invalidated.

2 files changed, 8 insertions, 19 deletions

diff --git a/cocoa/PlatCocoa.mm b/cocoa/PlatCocoa.mm
index 75c386f76..1141cca44 100644
--- a/cocoa/PlatCocoa.mm
+++ b/cocoa/PlatCocoa.mm
@@ -127,7 +127,7 @@ SurfaceImpl::SurfaceImpl() {
 	y = 0;
 	gc = NULL;
 
-	textLayout.reset(new QuartzTextLayout(nullptr));
+	textLayout.reset(new QuartzTextLayout());
 	codePage = 0;
 	verticalDeviceResolution = 0;
 
@@ -147,7 +147,6 @@ SurfaceImpl::~SurfaceImpl() {
 //--------------------------------------------------------------------------------------------------
 
 void SurfaceImpl::Clear() {
-	textLayout->setContext(nullptr);
 	if (bitmapData) {
 		bitmapData.reset();
 		// We only "own" the graphics context if we are a bitmap context
@@ -193,7 +192,6 @@ void SurfaceImpl::Init(SurfaceID sid, WindowID) {
 	Release();
 	gc = static_cast<CGContextRef>(sid);
 	CGContextSetLineWidth(gc, 1.0);
-	textLayout->setContext(gc);
 }
 
 //--------------------------------------------------------------------------------------------------
@@ -229,7 +227,6 @@ void SurfaceImpl::InitPixMap(int width, int height, Surface *surface_, WindowID
 		// and we have no use for the bitmap without the context
 		bitmapData.reset();
 	}
-	textLayout->setContext(gc);
 
 	// the context retains the color space, so we can release it
 	CGColorSpaceRelease(colorSpace);
@@ -863,7 +860,7 @@ void SurfaceImpl::DrawTextTransparent(PRectangle rc, Font &font_, XYPOSITION yba
 	CGColorRelease(color);
 
 	textLayout->setText(text, encoding, *style);
-	textLayout->draw(rc.left, ybase);
+	textLayout->draw(gc, rc.left, ybase);
 }
 
 //--------------------------------------------------------------------------------------------------
diff --git a/cocoa/QuartzTextLayout.h b/cocoa/QuartzTextLayout.h
index c33231176..a3ed910de 100644
--- a/cocoa/QuartzTextLayout.h
+++ b/cocoa/QuartzTextLayout.h
@@ -18,12 +18,8 @@
 
 class QuartzTextLayout {
 public:
-	/** Create a text layout for drawing on the specified context. */
-	explicit QuartzTextLayout(CGContextRef context) {
-		mString = NULL;
-		mLine = NULL;
-		stringLength = 0;
-		setContext(context);
+	/** Create a text layout for drawing. */
+	QuartzTextLayout() : mString(NULL), mLine(NULL), stringLength(0) {
 	}
 
 	~QuartzTextLayout() {
@@ -58,11 +54,12 @@ public:
 		CFRelease(str);
 	}
 
-	/** Draw the text layout into the current CGContext at the specified position.
+	/** Draw the text layout into a CGContext at the specified position.
+	* @param gc The CGContext in which to draw the text.
 	* @param x The x axis position to draw the baseline in the current CGContext.
 	* @param y The y axis position to draw the baseline in the current CGContext. */
-	void draw(float x, float y) {
-		if (mLine == NULL)
+	void draw(CGContextRef gc, float x, float y) {
+		if (!mLine)
 			return;
 
 		::CGContextSetTextMatrix(gc, CGAffineTransformMakeScale(1.0, -1.0));
@@ -89,12 +86,7 @@ public:
 		return stringLength;
 	}
 
-	inline void setContext(CGContextRef context) {
-		gc = context;
-	}
-
 private:
-	CGContextRef gc;
 	CFAttributedStringRef mString;
 	CTLineRef mLine;
 	CFIndex stringLength;