Eiffel Media API
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em.widget.background

Class EM_ALPHA_COLOR_BACKGROUND


Direct ancestors

EM_TRANSPARENT_BACKGROUND, EM_BITMAP_BACKGROUND

Creation

Features

Invariants

indexing

description

A one-color background with an alpha value.
Only widgets which have a parent can have a transparent background.
This means that a widget wich is placed directly on a EM_COMPONENT_SCENE
can not have a transparent background.

date

$Date: 2005/10/23 11:10:45 $

revision

$Revision: 1.9 $

class

EM_ALPHA_COLOR_BACKGROUND

inherit

EM_TRANSPARENT_BACKGROUND
EM_BITMAP_BACKGROUND

create

make_from_color (a_color: like color)

-- Initialise background with a_color.

require
a_color_not_void: a_color /= Void
ensure
color_set: color = a_color

feature -- Access

color: EM_COLOR

-- Background color

feature -- Element change

set_alpha_value (alpha: INTEGER)

-- Set alpha value of color to alpha.

require
alpha_in_range: 0 <= alpha and alpha <= 255
ensure
alpha_set: color.alpha = alpha
set_color (a_color: like color)

-- Set color to a_color.

require
a_color_not_void: a_color /= Void
ensure
color_set: color = a_color

feature -- Drawing

draw_on (a_widget: EM_WIDGET)

-- Draw background ona_widget.

-- (From EM_BACKGROUND)

require
a_widget_not_void: a_widget /= Void

invariant

color_not_void: color /= Void

-- From ANY
reflexive_equality: standard_is_equal (Current)
reflexive_conformance: conforms_to (Current)

bitmap_not_void: bitmap /= Void

end