bl_ui_drag_panel.py

from . bl_ui_widget import * 

class BL_UI_Drag_Panel(BL_UI_Widget):
    
    def __init__(self, x, y, width, height):
        super().__init__(x,y, width, height)
        self.drag_offset_x = 0
        self.drag_offset_y = 0
        self.is_drag = False
        self.widgets = []

    def set_location(self, x, y):
        super().set_location(x,y)
        self.layout_widgets()

    def add_widget(self, widget):
        self.widgets.append(widget)
        
    def add_widgets(self, widgets):
        self.widgets = widgets
        self.layout_widgets()
        
    def layout_widgets(self):
        for widget in self.widgets:
            widget.update(self.x_screen + widget.x, self.y_screen + widget.y)   
    
    def update(self, x, y):
        super().update(x - self.drag_offset_x, y + self.drag_offset_y)
    
    def child_widget_focused(self, x, y):
        for widget in self.widgets:
            if widget.is_in_rect(x, y):
                return True       
        return False
    
    def mouse_down(self, x, y):
        if self.child_widget_focused(x, y):
            return False
        
        if self.is_in_rect(x,y):
            height = self.get_area_height()
            self.is_drag = True
            self.drag_offset_x = x - self.x_screen
            self.drag_offset_y = y - (height - self.y_screen)
            return True
        
        return False

    def mouse_move(self, x, y):
        if self.is_drag:
            height = self.get_area_height()
            self.update(x, height - y)
            self.layout_widgets()

    def mouse_up(self, x, y):
        self.is_drag = False
        self.drag_offset_x = 0
        self.drag_offset_y = 0