Avoid window flashing white when first shown

This only applies to the Core Text renderer.

src/MacVim/MMVimView.h

@@ -26,6 +26,7 @@
     MMTextView          *textView;
     NSMutableArray      *scrollbars;
     NSRect              lastTextViewFrame;
+    BOOL                isDirty;
 }
 
 - (MMVimView *)initWithFrame:(NSRect)frame vimController:(MMVimController *)c;
@@ -57,5 +58,6 @@
 - (void)viewDidEndLiveResize;
 - (void)setFrameSize:(NSSize)size;
 - (void)setFrame:(NSRect)frame;
+- (void)markDirty;
 
 @end

src/MacVim/MMVimView.m

@@ -191,6 +191,23 @@ enum {
 
 - (void)drawRect:(NSRect)rect
 {
+    if (isDirty) {
+        // Clear the entire view
+        CGContextRef ctx = [[NSGraphicsContext currentContext] graphicsPort];
+        NSRect rect = [self bounds];
+        NSColor *color = [textView defaultBackgroundColor];
+        CGContextSetBlendMode(ctx, kCGBlendModeCopy);
+        CGContextSetRGBFillColor(ctx,
+                                 [color redComponent],
+                                 [color greenComponent],
+                                 [color blueComponent],
+                                 [color alphaComponent]);
+        CGContextFillRect(ctx, *(CGRect*)&rect);
+        CGContextSetBlendMode(ctx, kCGBlendModeNormal);
+
+        isDirty = NO;
+    }
+
     NSRect textViewFrame = [textView frame];
     if (!NSEqualRects(lastTextViewFrame, textViewFrame)) {
         // If the text view's frame changes we copy the contents of the old
@@ -627,6 +644,13 @@ enum {
     [self frameSizeMayHaveChanged];
 }
 
+- (void)markDirty
+{
+    // When the view is marked as dirty, the entire background will be cleared
+    // the next time the view is redrawn.
+    isDirty = YES;
+}
+
 @end // MMVimView
 
 

src/MacVim/MMWindowController.m

@@ -270,6 +270,7 @@
     // later).
     if (!setupDone) return;
 
+    [vimView markDirty];
     [[MMAppController sharedInstance] windowControllerWillOpen:self];
     [[self window] makeKeyAndOrderFront:self];
 }