更新drawmain.py, paint.kv

drawmain.py

+# -*- coding: utf-8 -*-
+"""
+Created on Fri Sep 10 13:58:05 2021
+
+@author: flameabc
+@dec:  draw
+简易画板，熟悉.kv文件，布局，按钮分布。。。
+"""
+
+from kivy.app import App
+from kivy.graphics import Line, Color
+from kivy.uix.widget import Widget
+from kivy.utils import get_color_from_hex
+from kivy.uix.behaviors import ToggleButtonBehavior
+from kivy.uix.togglebutton import ToggleButton
+
+
+
+class DrawCanvasWidget(Widget):
+
+    def __init__(self, **kwargs):
+
+        super().__init__(**kwargs)
+        """ 设置默认颜色 """
+        self.change_color(get_color_from_hex('#19caad'))
+        self.line_width = 2
+
+    def on_touch_down(self, touch):
+        """ 触摸显示轨迹 """
+        if Widget.on_touch_down(self, touch):
+            return
+
+        with self.canvas:
+            touch.ud['current_line'] = Line(points=(touch.x, touch.y), width=self.line_width)
+
+    def on_touch_move(self, touch):
+        """ 连线 """
+        if 'current_line' in touch.ud:
+            touch.ud['current_line'].points += (touch.x, touch.y)
+
+    def change_color(self, new_color):
+        """ 调色 """
+        self.last_color = new_color
+        self.canvas.add(Color(*new_color))
+
+    def change_line_width(self, line_width='Normal'):
+        """ 线宽 """
+        self.line_width = {'Thin': 1, 'Normal': 2, 'Thick': 4}[line_width]
+
+    def clear_canvas(self):
+        """ 清空 """
+        saved = self.children[:]
+        self.clear_widgets()
+        self.canvas.clear()
+        for widget in saved:
+            self.add_widget(widget)
+        self.change_color(self.last_color)
+
+class FrameToggleButton(ToggleButton):
+    """ 当前按钮添加边框 """
+    def do_press(self):
+        """ 点击改变状态 """
+        if self.state == 'Normal':
+            ToggleButtonBehavior.do_press(self)
+
+
+class PaintApp(App):
+
+    def build(self):
+
+        self.draw_canvas_widget = DrawCanvasWidget()
+
+        return self.draw_canvas_widget
+
+
+if __name__ == '__main__':
+    PaintApp().run()
+

paint.kv

+#:import C kivy.utils.get_color_from_hex
+    
+<BottomColorButton@ToggleButton>:
+    
+    group: 'color'
+    background_normal: 'radio_background_normal.png'
+    background_down: 'radio_background_down.png'
+    border: (3, 3, 3, 3)
+    on_release: app.draw_canvas_widget.change_color(self.background_color)
+    
+<LineWidgetButton@ToggleButton>:
+    
+    group: 'line_width'
+    color: C('#2c3e50')
+    background_color: C('#ecf0f1')
+    background_normal: 'radio_background_normal.png'
+    background_down: 'radio_background_down.png'
+    border: (3, 3, 3, 3)
+    on_release: app.draw_canvas_widget.change_line_width(self.text)
+
+<DrawCanvasWidget>:
+
+    canvas.before:
+        Color:
+            rgba: 1, 1, 1, 1
+        Rectangle:
+            # self here refers to the widget i.e FloatLayout
+            pos: self.pos
+            size: self.size
+    BoxLayout:
+    
+        orientation: 'horizontal'
+        padding: 2
+        spacing: 2
+        x: 0
+        top: root.top
+        size_hint: None, None
+        size: 280, 40
+        LineWidgetButton:        
+            text: 'Thin'
+        LineWidgetButton:        
+            text: 'Normal'
+            state: 'down'
+        LineWidgetButton:        
+            text: 'Thick'
+        Button:
+            text: 'Clear'
+            on_release: root.clear_canvas()
+
+    BoxLayout:
+        id: botton_box
+        orientation: 'horizontal'
+
+        padding: 2
+        spacing: 2
+        size: root.width, 40
+        
+        BottomColorButton:
+            background_color: C('#19caad')
+            state: 'down'
+        BottomColorButton:             
+            background_color: C('#8cc7b5')         
+        BottomColorButton:             
+            background_color: C('#a0eee1')         
+        BottomColorButton:
+            background_color: C('#bee7e9')         
+        BottomColorButton:             
+            background_color: C('#beedc7')         
+        BottomColorButton:             
+            background_color: C('#d6d5b7')
+        BottomColorButton:             
+            background_color: C('#d1ba74')         
+        BottomColorButton:             
+            background_color: C('#e6ceac')         
+        BottomColorButton:             
+            background_color: C('#ecad9e')         
+        BottomColorButton:             
+            background_color: C('#f4606c')         
+        BottomColorButton:             
+            background_color: C('#3498db')         
+        BottomColorButton:             
+            background_color: C('#1abc9c')         
+        BottomColorButton:             
+            background_color: C('#2ecc71')         
+        BottomColorButton:             
+            background_color: C('#f1c40f')         
+        BottomColorButton:             
+            background_color: C('#e67e22')         
+        BottomColorButton:             
+            background_color: C('#e74c3c')         
+        BottomColorButton:             
+            background_color: C('#9b59b6')         
+        BottomColorButton:
+            background_color: C('#ecf0f1')         
+        BottomColorButton:             
+            background_color: C('#95a5a6')         
+        BottomColorButton:             
+            background_color: C('#000000')