DrawTextLayout alignment

[mischnic]

On macOS, the other alignment types don't really respect uiDrawTextLayoutParams.Width, but rather the longest line:

[mischnic]

The problem is that

libui/darwin/drawtext.m

Lines 67 to 75 in 2f0e6e9

	cgwidth = (CGFloat) (p->Width);
	if (cgwidth < 0)
	cgwidth = CGFLOAT_MAX;
	self->size = CTFramesetterSuggestFrameSizeWithConstraints(self->framesetter,
	range,
	// TODO kCTFramePathWidthAttributeName?
	NULL,
	CGSizeMake(cgwidth, CGFLOAT_MAX),
	&unused); // not documented as accepting NULL (TODO really?)

creates a frame which is smaller than p->Width and the aligned paragraphs use that smaller frame.

Fix (not very clean):

diff --git a/darwin/drawtext.m b/darwin/drawtext.m
index c04b402b..22de269c 100644
--- a/darwin/drawtext.m
+++ b/darwin/drawtext.m
@@ -76,6 +76,7 @@
		cgwidth = (CGFloat) (p->Width);
		if (cgwidth < 0)
			cgwidth = CGFLOAT_MAX;
		self->size = CTFramesetterSuggestFrameSizeWithConstraints(self->framesetter,
			range,
			// TODO kCTFramePathWidthAttributeName?
			NULL,
			CGSizeMake(cgwidth, CGFLOAT_MAX),
			&unused);			// not documented as accepting NULL (TODO really?)

                rect.origin = CGPointZero;
                rect.size = self->size;
+               rect.size.width = cgwidth;
                self->path = CGPathCreateWithRect(rect, NULL);
                self->frame = CTFramesetterCreateFrame(self->framesetter,
                        range,
			self->path,
			// TODO kCTFramePathWidthAttributeName?
			NULL);

[andlabs]

I am also going to add a tiny string option to that example program, temporarily to test things like this while I don't have a more "proper" test framework (and the tester program is getting to be quite much). Not sure if I will use that exact fix or not; I forget what my previous drawtext code did.

[mischnic]

I forget what my previous drawtext code did.

libui/darwin/drawtext.m

Lines 511 to 532 in 7891cd8

	static void mkFramesetter(uiDrawTextLayout *layout, struct framesetter *fs)
	{
	CFRange fitRange;
	CGFloat width;
	fs->fs = CTFramesetterCreateWithAttributedString(layout->mas);
	if (fs->fs == NULL)
	complain("error creating CTFramesetter object in mkFramesetter()");
	// TODO kCTFramePathWidthAttributeName?
	fs->frameAttrib = NULL;
	width = layout->width;
	if (layout->width < 0)
	width = CGFLOAT_MAX;
	// TODO these seem to be floor()'d or truncated?
	fs->extents = CTFramesetterSuggestFrameSizeWithConstraints(fs->fs,
	CFRangeMake(0, 0),
	fs->frameAttrib,
	CGSizeMake(width, CGFLOAT_MAX),
	&fitRange); // not documented as accepting NULL
	}

libui/darwin/drawtext.m

Lines 569 to 600 in 7891cd8

	void doDrawText(CGContextRef c, CGFloat cheight, double x, double y, uiDrawTextLayout *layout)
	{
	struct framesetter fs;
	CGRect rect;
	CGPathRef path;
	CTFrameRef frame;
	prepareContextForText(c, cheight, &y);
	mkFramesetter(layout, &fs);
	// oh, and since we're flipped, y is the bottom-left coordinate of the rectangle, not the top-left
	// since we are flipped, we subtract
	y -= fs.extents.height;
	rect.origin = CGPointMake(x, y);
	rect.size = fs.extents;
	path = CGPathCreateWithRect(rect, NULL);
	frame = CTFramesetterCreateFrame(fs.fs,
	CFRangeMake(0, 0),
	path,
	fs.frameAttrib);
	if (frame == NULL)
	complain("error creating CTFrame object in doDrawText()");
	CTFrameDraw(frame, c);
	CFRelease(frame);
	CFRelease(path);
	freeFramesetter(&fs);
	CGContextRestoreGState(c);
	}