#1309 display color gradients

git-svn-id: https://xpra.org/svn/Xpra/trunk@16301 3bb7dfac-3a0b-4e04-842a-767bc560f471

src/tests/xpra/test_apps/colors_gradient.py

@@ -0,0 +1,66 @@
+#!/usr/bin/env python
+
+import cairo
+import gi
+gi.require_version('Gtk', '3.0')    #@UndefinedVariable
+
+from gi.repository import Gtk, Gdk  #@UnresolvedImport
+
+class TransparentColorWindow(Gtk.Window):
+
+    def __init__(self):
+        super(TransparentColorWindow, self).__init__()
+        self.set_position(Gtk.WindowPosition.CENTER)
+        self.set_default_size(1024, 768)
+        self.set_app_paintable(True)
+        self.set_events(Gdk.EventMask.KEY_PRESS_MASK)
+        self.connect("draw", self.area_draw)
+        self.connect("destroy", Gtk.main_quit)
+        self.show_all()
+
+    def area_draw(self, widget, cr):
+        #Clear everything:
+        cr.save()
+        cr.set_operator(cairo.OPERATOR_CLEAR)
+        ww, wh = widget.get_size()
+        cr.rectangle(0, 0, ww, wh)
+        cr.fill()
+        cr.restore()
+
+        c = 8
+
+        def paint_block(x, y, w, h, R=255, G=255, B=255, label=""):
+            cr.set_operator(cairo.OPERATOR_SOURCE)
+            for i in range(w):
+                v = float(i)/float(w)
+                cr.save()
+                r = max(0, float(R)*v/255.0)
+                g = max(0, float(G)*v/255.0)
+                b = max(0, float(B)*v/255.0)
+                cr.set_source_rgb(r, g, b)
+                cr.rectangle(x+i, y, 1, h)
+                cr.fill()
+                cr.restore()
+            if label:
+                cr.set_font_size(32)
+                cr.set_source_rgb(1, 1, 1)
+                cr.move_to(x+w//2-12, y+wh//(c*2)+8)
+                cr.show_text(label)
+
+        #Red block
+        paint_block(0, 0,       ww, wh/c,   255, 0, 0, "R")
+        #Green block:
+        paint_block(0, wh//c,   ww, 2*wh/c, 0, 254, 0, "G")
+        #Blue block:
+        paint_block(0, 2*wh//c, ww, 3*wh/c, 0, 0, 253, "B")
+        #Black Shade Blocks:
+        paint_block(0, 3*wh//c, ww, 4*wh/c,     255, 255, 255)
+        paint_block(0, 4*wh//c, ww, 5*wh/c,     127, 127, 127)
+        paint_block(0, 5*wh//c, ww, 6*wh/c,     63, 63, 63)
+        paint_block(0, 6*wh//c, ww, 7*wh/c,     31, 31, 31)
+        paint_block(0, 7*wh//c, ww, 8*wh/c,     15, 15, 15)
+
+import signal
+signal.signal(signal.SIGINT, lambda x,y : Gtk.main_quit)
+TransparentColorWindow()
+Gtk.main()