Titles: Don't pollute temp dir with title previews

[ferdnyc]

Fixes #3518

[jonoomph]

LGTM. I really thought we were using our QtImageReader to rasterize the title previews, so it would use our rsvg library (if compiled). Hmmm, I guess that is for another day. 😉

[ferdnyc]

LGTM. I really thought we were using our QtImageReader to rasterize the title previews, so it would use our rsvg library (if compiled). Hmmm, I guess that is for another day.

Oh, no, we are. It uses reader.GetFrame().Thumbnail() to write the preview out to the tmp_filename, then reads it back in via QPixmap().load(). Then it adds it to the QGraphicsScene. (The variable name svg for the QPixmap is, arguably, slightly confusing perhaps.)

openshot-qt/src/windows/title_editor.py

Lines 157 to 177 in 0d3da87

	# Create a clip object and get the reader
	clip = openshot.Clip(self.filename)
	reader = clip.Reader()
	# Open reader
	reader.Open()
	# Overwrite temp file with thumbnail image and close readers
	reader.GetFrame(1).Thumbnail(
	tmp_filename,
	self.graphicsView.width(),
	self.graphicsView.height(),
	"", "", "#000", False, "png", 85, 0.0)
	reader.Close()
	clip.Close()
	# Attempt to load saved thumbnail
	svg = QtGui.QPixmap()
	if not svg.load(tmp_filename):
	log.error("Couldn't load title preview from {}".format(tmp_filename))
	return