note
	description: "Eiffel Vision pick and drop source, Cocoa implementation."
	author: "Daniel Furrer"
	keywords: "pick and drop, drag and drop, source, PND, DND"
	date: "$Date$"
	revision: "$Revision$"

deferred class
	EV_PICK_AND_DROPABLE_IMP

inherit
	EV_PICK_AND_DROPABLE_I
		export
			{EV_INTERMEDIARY_ROUTINES}
				execute
		redefine
			interface
		end

	EV_PICK_AND_DROPABLE_ACTION_SEQUENCES_IMP

	EV_ANY_IMP
		redefine
			interface
		end

feature {EV_ANY_I, EV_INTERMEDIARY_ROUTINES} -- Implementation

	screen_x: INTEGER
			-- Horizontal position of the client area on screen,
		deferred
		end

	screen_y: INTEGER
			-- Vertical position of the client area on screen,
		deferred
		end

	x_position: INTEGER
			-- Horizontal offset relative to parent `x_position'.
			-- Unit of measurement: screen pixels.
		deferred
		end

	y_position: INTEGER
			-- Vertical offset relative to parent `y_position'.
			-- Unit of measurement: screen pixels.
		deferred
		end

feature {EV_ANY_I, EV_INTERMEDIARY_ROUTINES,  LAYOUT_INSPECTOR} -- Implementation

	top_level_window_imp: detachable EV_WINDOW_IMP
			-- Top level window that contains `Current'.
		do
			check
				implement_in_subclass: false
			end
		end

	widget_imp_at_pointer_position: detachable EV_WIDGET_IMP
			-- Widget implementation at current mouse pointer position (if any)
		do
			--create Result
		end

	set_pointer_style (a_cursor: EV_POINTER_STYLE)
			-- Assign `a_cursor' to `pointer_style'.
		do
		end

	internal_set_pointer_style (a_cursor: EV_POINTER_STYLE)
			-- Assign `a_cursor' to `pointer_style', used for PND
		do
		end

	pointer_style: detachable EV_POINTER_STYLE
			-- Cursor displayed when the pointer is over this widget.
			-- Position retrieval.

	width: INTEGER
			-- Horizontal size measured in pixels.
		deferred
		end

	height: INTEGER
			-- Vertical size measured in pixels.
		deferred
		end

	show
			-- Request that `Current' be displayed when its parent is.
		do
		end

feature -- Implementation

	call_button_event_actions (
			a_type: INTEGER;
			a_x, a_y, a_button: INTEGER;
			a_x_tilt, a_y_tilt, a_pressure: DOUBLE;
			a_screen_x, a_screen_y: INTEGER)

		do
		end

feature {NONE} -- Implementation

	enable_capture
			-- Grab all the mouse and keyboard events.
		do
			internal_has_capture := True
		end

	disable_capture
			-- Ungrab all the mouse and keyboard events.
			--| Used by pick and drop.
		do
			internal_has_capture := False
		end

	has_capture: BOOLEAN
			-- Does Current have the keyboard and mouse event capture?
		do
			Result := internal_has_capture
		end

	internal_has_capture: BOOLEAN

feature -- Implementation

	enable_transport
			-- Activate pick/drag and drop mechanism.
 		do
 			is_transport_enabled := True
		end

	disable_transport
			-- Deactivate pick/drag and drop mechanism.
		do
 			is_transport_enabled := False
		end

	pre_pick_steps (a_x, a_y, a_screen_x, a_screen_y: INTEGER)
			-- Steps to perform before transport initiated.
		do
		end

	is_dockable: BOOLEAN
			-- Is `Current' dockable?
		deferred
		end

	set_to_drag_and_drop: BOOLEAN
			-- Set `Current' to drag and drop mode.
		do
		end

	able_to_transport (a_button: INTEGER): BOOLEAN
			-- Is `Current' able to initiate transport with `a_button'.
		do
		end

	on_mouse_button_event (
			a_type: INTEGER;
			a_x, a_y, a_button: INTEGER;
			a_x_tilt, a_y_tilt, a_pressure: DOUBLE;
			a_screen_x, a_screen_y: INTEGER)

			-- Handle mouse button events.
		do
		end

	start_transport (
			a_x, a_y, a_button: INTEGER; a_press: BOOLEAN
			a_x_tilt, a_y_tilt, a_pressure: DOUBLE;
			a_screen_x, a_screen_y: INTEGER; a_menu_only: BOOLEAN)

			-- Initialize a pick and drop transport.
		do
		end

	ready_for_pnd_menu (a_button: INTEGER): BOOLEAN
			-- Will `Current' display a menu with button `a_button'.
		do
		end

	end_transport (a_x, a_y, a_button: INTEGER; a_x_tilt, a_y_tilt, a_pressure: DOUBLE; a_screen_x, a_screen_y: INTEGER)
			-- End a pick and drop transport.
		do
		end

	post_drop_steps (a_button: INTEGER)
			-- Steps to perform once an attempted drop has happened.
		do
		end

	draw_rubber_band
			-- Draw a segment between initial pick point and `destination'.
		do
		end

	erase_rubber_band
			-- Erase previously drawn rubber band.
		do
		end

	pnd_screen: EV_SCREEN
			-- Screen object used for drawing PND transport line
		once
			create Result
		end

	real_pointed_target: detachable EV_PICK_AND_DROPABLE
			-- Hole at mouse position
		do
		end

	create_drop_actions: EV_PND_ACTION_SEQUENCE
			-- Create and initialize `drop_actions' for `Current'
		do
			create Result
			attached_interface.init_drop_actions (Result)
		end

feature {EV_ANY, EV_ANY_I} -- Implementation

	interface: detachable EV_PICK_AND_DROPABLE note option: stable attribute end;

end -- class EV_PICK_AND_DROPABLE_IMP