Merge pull request #1674 from firefish5000/firefish5000-imagebox

Add null check to set imagebox to blank state

lib/wibox/widget/imagebox.lua

@@ -91,7 +91,7 @@ function imagebox:set_image(image)
         end
     end
 
-    image = surface.load(image)
+    image = image and surface.load(image)
 
     if image then
         local w = image.width

spec/wibox/widget/imagebox_spec.lua

@@ -0,0 +1,46 @@
+---------------------------------------------------------------------------
+-- @author Emmanuel Lepage Vallee
+-- @copyright 2017 Emmanuel Lepage Vallee
+---------------------------------------------------------------------------
+
+local imagebox = require("wibox.widget.imagebox")
+local cairo = require("lgi").cairo
+
+describe("wibox.widget.imagebox", function()
+    local widget
+    before_each(function()
+        widget = imagebox()
+    end)
+
+    describe("setting image", function()
+        local redraw_needed, layout_changed
+        before_each(function()
+            widget:connect_signal("widget::redraw_needed", function()
+                redraw_needed = redraw_needed + 1
+            end)
+            widget:connect_signal("widget::layout_changed", function()
+                layout_changed = layout_changed + 1
+            end)
+            redraw_needed, layout_changed = 0, 0
+        end)
+
+        it("set_image", function()
+            assert.is.equal(widget._private.image, nil)
+            assert.is.equal(0, redraw_needed)
+            assert.is.equal(0, layout_changed)
+
+            local img = cairo.ImageSurface(cairo.Format.ARGB32, 20, 20);
+            widget:set_image(img)
+            assert.is.equal(widget._private.image, img)
+            assert.is.equal(1, redraw_needed)
+            assert.is.equal(1, layout_changed)
+
+            widget:set_image(nil)
+            assert.is.equal(widget._private.image, nil)
+            assert.is.equal(2, redraw_needed)
+            assert.is.equal(2, layout_changed)
+        end)
+    end)
+end)
+
+-- vim: filetype=lua:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:textwidth=80