[ruby-gnome2-cvs] ruby-gnome2/ruby-gnome2@c9d8760 [master] Add css_blendmodes demo

[cedlemo <nu...@co...>]

cedlemo	2017-08-29 02:19:01 +0900 (Tue, 29 Aug 2017)

  New Revision: c9d876071fedae2feeb027fc0942b3d4b19a5e55
  https://github.com/ruby-gnome2/ruby-gnome2/commit/c9d876071fedae2feeb027fc0942b3d4b19a5e55

  Merged b3f3ba3: Merge pull request #1098 from cedlemo/gtk3_sample_gtk_demo_css_blendmodes_rb

  Message:
    Add css_blendmodes demo

  Added files:
    gtk3/sample/gtk-demo/css_blendmodes.rb

  Added: gtk3/sample/gtk-demo/css_blendmodes.rb (+90 -0) 100644
===================================================================
--- /dev/null
+++ gtk3/sample/gtk-demo/css_blendmodes.rb    2017-08-29 02:19:01 +0900 (4cd5ec612)
@@ -0,0 +1,90 @@
+# Copyright (c) 2017 Ruby-GNOME2 Project Team
+# This program is licenced under the same licence as Ruby-GNOME2.
+#
+=begin
+=  Theming/CSS Blend Modes
+
+ You can blend multiple backgrounds using the CSS blend modes available.
+=end
+
+BlendMode = Struct.new(:name, :id)
+
+class CssBlendmodesDemo
+  def initialize(main_window)
+    @builder = Gtk::Builder.new(:resource => "/css_blendmodes/blendmodes.ui")
+    @window = @builder["window"]
+    @window.transient_for = main_window
+
+    # Setup the CSS provider for window
+    @provider  = Gtk::CssProvider.new
+    Gtk::StyleContext.add_provider_for_screen(Gdk::Screen.default,
+                                              @provider,
+                                              Gtk::StyleProvider::PRIORITY_APPLICATION)
+
+    initialize_blend_modes
+    setup_listbox
+  end
+
+  def run
+    if !@window.visible?
+      @window.show_all
+    else
+      @window.destroy
+    end
+    @window
+  end
+
+  private
+
+  def initialize_blend_modes
+    @blend_modes = []
+    @blend_modes << BlendMode.new("Color", "color")
+    @blend_modes << BlendMode.new("Color (burn)", "color-burn")
+    @blend_modes << BlendMode.new("Color (dodge)", "color-dodge")
+    @blend_modes << BlendMode.new("Darken", "darken")
+    @blend_modes << BlendMode.new("Difference", "difference")
+    @blend_modes << BlendMode.new("Exclusion", "exclusion")
+    @blend_modes << BlendMode.new("Hard Light", "hard-light")
+    @blend_modes << BlendMode.new("Hue", "hue")
+    @blend_modes << BlendMode.new("Lighten", "lighten")
+    @blend_modes << BlendMode.new("Luminosity", "luminosity")
+    @blend_modes << BlendMode.new("Multiply", "multiply")
+    @blend_modes << BlendMode.new("Normal", "normal")
+    @blend_modes << BlendMode.new("Overlay", "overlay")
+    @blend_modes << BlendMode.new("Saturate", "saturate")
+    @blend_modes << BlendMode.new("Screen", "screen")
+    @blend_modes << BlendMode.new("Soft Light", "soft-light")
+  end
+
+  def setup_listbox
+    normal_row = nil
+    listbox = Gtk::ListBox.new
+    @builder["scrolledwindow"].add(listbox)
+
+    listbox.signal_connect "row-activated" do |widget, w_row, w_provider|
+      blend_mode = @blend_modes[w_row.index].id
+      update_css_for_blend_mode(blend_mode)
+    end
+
+    @blend_modes.each do |blend_mode|
+      row = Gtk::ListBoxRow.new
+      label = Gtk::Label.new(blend_mode.name)
+      label.xalign = 0
+      row.add(label)
+      listbox.add(row)
+
+      normal_row = row if blend_mode.id == "normal"
+    end
+
+    # select the "normal" row
+    listbox.select_row(normal_row)
+    normal_row.signal_emit("activate")
+    normal_row.grab_focus
+  end
+
+  def update_css_for_blend_mode(blend_mode)
+    raw_css = Gio::Resources.lookup_data("/css_blendmodes/css_blendmodes.css", 0)
+    css = sprintf(raw_css, blend_mode, blend_mode, blend_mode)
+    @provider.load_from_data(css)
+  end
+end