Testcase for text_extents function

Originally committed to SVN as r824.

automation/tests/test-text_extents.lua

@@ -0,0 +1,29 @@
+-- Automation 4 test file
+-- Test the result of the text_extents function
+
+script_name = "Test text_extents"
+script_description = "Test what the result of text_extents is on a fixed string on all styles in the file"
+script_author = "Niels Martin Hansen"
+script_version = "1"
+
+
+function test_te(subtitles, selected_lines, active_line)
+	local teststring = "Test"
+	
+	aegisub.debug.out("Test string is '" .. teststring .. "'\n")
+	
+	local styles = {}
+	for i = 1, #subtitles do
+		local l = subtitles[i]
+		if l.class == "style" then
+			aegisub.debug.out(" - - -\n")
+			aegisub.debug.out("Found style: " .. l.name .. "\n")
+			local width, height, descent, extlead = aegisub.text_extents(l, teststring)
+			aegisub.debug.out(string.format("Width: %.2f  Height: %.2f  Descent: %.2f  Ext. lead: %.2f\n", width, height, descent, extlead))
+		end
+		aegisub.progress.set(i/#subtitles*100)
+	end
+end
+
+
+aegisub.register_macro("Test text_extents", "Show the result of the text_extents function for all styles in the file", test_te, nil)