[Android] fix: screen height wrong. Not catering correctly for action bar

Author: hboon

flow/ui/android/navigation.rb

@@ -1,6 +1,21 @@
 class UI::Navigation
   attr_reader :root_screen
 
+  #In pixels
+  def self.bar_height
+    value = Android::Util::TypedValue.new
+    if UI.context.theme.resolveAttribute(Android::R::Attr::ActionBarSize, value, true)
+      Android::Util::TypedValue.complexToDimensionPixelSize(value.data, UI::context.resources.displayMetrics)
+    else
+      resource_id = UI.context.resources.getIdentifier('action_bar_default_height', 'dimen', 'android')
+      if resource_id
+        UI.context.resources.getDimensionPixelSize(resource_id)
+      else
+        0
+      end
+    end
+  end
+
   def initialize(root_screen)
     @root_screen = root_screen
     @root_screen.navigation = self
@@ -17,7 +32,8 @@ def hide_bar
       bar.hide
       Task.after 0.05 do
         screen = @current_screens.last
-        screen.view.height += (bar.height / UI.density)
+        bar_height = bar.height>0 ? bar.height : self.class.bar_height
+        screen.view.height += (bar_height / UI.density)
         screen.view.update_layout
       end
     end
@@ -29,7 +45,8 @@ def show_bar
       bar.show
       Task.after 0.05 do
         screen = @current_screens.last
-        screen.view.height -= (bar.height / UI.density)
+        bar_height = bar.height>0 ? bar.height : self.class.bar_height
+        screen.view.height -= (bar_height / UI.density)
         screen.view.update_layout
       end
     end

flow/ui/android/screen.rb

@@ -109,6 +109,7 @@ def view
         if resource_id > 0
           view_height -= UI.context.resources.getDimensionPixelSize(resource_id)
         end
+        view_height -= UI::Navigation.bar_height
 
         view.width = main_screen_metrics.width / UI.density
         view.height = view_height / UI.density