lighttroupe/luz

class GuiGrid < GuiBox
    easy_accessor :spacing_x, :spacing_y, :item_scale_x, :item_scale_y, :min_columns

    DEFAULT_MIN_COLUMNS = 3

    def each_with_positioning
        num_per_row = column_count
        distance_x = (1.0 / num_per_row)
        distance_y = distance_x

        with_positioning {
            @contents.each_with_index { |gui_object, index|
                row_index, column_index = index.divmod(num_per_row)
                with_translation(-0.5 + (distance_x / 2.0) + (column_index * distance_x), 0.5 - (distance_y / 2.0) - (row_index * distance_y)) {
                    with_scale((1.0 / num_per_row) * (item_scale_x || 1.0), (1.0 / num_per_row) * (item_scale_y || 1.0)) {
                        yield gui_object
                    }
                }
            }
        }
    end

    def column_count
        min_columns || DEFAULT_MIN_COLUMNS        # TODO: default value
    end

    def gui_render
        return if hidden?
        each_with_positioning { |gui_object| gui_object.gui_render }
    end

    def hit_test_render!
        return if hidden?
        each_with_positioning { |gui_object| gui_object.hit_test_render! }
    end

    def select_next!(number=1)
        if (index = selected_index)
            if (index + number) >= @contents.size
                set_selection(@contents.last)
                return
            end
        end
        super
    end

    def select_previous!(number=1)
        if (index = selected_index)
            if (index - number) < 0
                set_selection(@contents.first)
                return
            end
        end
        super
    end

    def on_key_press(key)
        return super if key.control?

        if key.alt?
            case key
            when 'up'
                selection = @selection.first
                move_child_up(selection, column_count) if selection
            when 'down'
                selection = @selection.first
                move_child_down(selection, column_count) if selection
            when 'left'
                selection = @selection.first
                move_child_up(selection) if selection
            when 'right'
                selection = @selection.first
                move_child_down(selection) if selection
            else
                super
            end
        else
            case key
            when 'up'
                select_previous!(column_count)
                selection_grab_focus!
            when 'down'
                select_next!(column_count)
                selection_grab_focus!
            when 'left'
                select_previous!
                selection_grab_focus!
            when 'right'
                select_next!
                selection_grab_focus!
            else
                super
            end
        end
    end
end