command_prompt: Add cursor and basic cursor functionality

command_prompt.py

@@ -1,5 +1,6 @@
 from kivy.uix.label import Label
 from kivy.core.window import Window
+from kivy.graphics import Color,Rectangle
 
 class Command_prompt(Label):
     
@@ -10,21 +11,73 @@ class Command_prompt(Label):
         # insert mode
         self.insert=False
 
+        # cursor position
+        self.cursor=0
+        self.cursor_width=9
+
+        # the text, with no color information
+        self.raw_text=""
+
         # init Label
         super(Command_prompt,self).__init__(**kwargs)
 
         self.keyboard = Window.request_keyboard(None,self,"text")
         self.keyboard.bind(on_textinput=self.on_textinput,on_key_down=self.on_key_down)
 
+        self.draw()
+
+    def draw(self):
+        with self.canvas.before:
+            # background
+            Color(0,0,0)
+            Rectangle(pos=self.pos,size=self.size)
+            # cursor
+            Color(1,1,1)
+            Rectangle(pos=(self.pos[0]+self.cursor*self.cursor_width,self.pos[1]),size=(self.cursor_width,self.height))
+
+        # make text under cursor black
+        if self.cursor<len(self.raw_text):
+            self.text=self.raw_text[:self.cursor]+"[color=000]"+self.raw_text[self.cursor]+"[/color]"+self.raw_text[self.cursor+1:]
+        else:
+            self.text=self.raw_text
+
     def on_key_down(self, keyboard, keycode, text, modifiers):
+        print(keycode,text,modifiers)
         if self.insert:
             if keycode[1]=="enter":
                 self.insert=False
-                self.text=""
+                self.set_text("")
+            elif keycode[1]=="left":
+                self.move_cursor(-1)
+            elif keycode[1]=="right":
+                self.move_cursor(1)
 
     def on_textinput(self,window,text):
+        print(text)
         if self.insert:
-            self.text+=text
+            self.append_text_at_cursor(text)
         elif text==':':
-            self.text+=text
+            self.append_text_at_cursor(text)
             self.insert=True
+
+    # append to text at position of cursor
+    def append_text_at_cursor(self,text):
+        if self.cursor==len(self.raw_text):
+            self.raw_text+=text
+        else:
+            self.raw_text=self.raw_text[:self.cursor]+text+self.raw_text[self.cursor:]
+        self.cursor+=len(text)
+        self.draw()
+
+    # set text in prompt
+    def set_text(self,text):
+        self.raw_text=text
+        self.cursor=len(text)
+        self.draw()
+
+    # move cursor n steps to right (left if negative)
+    def move_cursor(self,n):
+        if n==0 or (n>0 and self.cursor==len(self.raw_text)) or (n<0 and self.cursor==0):
+            return
+        self.cursor=max(0,min(len(self.raw_text),self.cursor+n))
+        self.draw()

jam.kv

@@ -16,14 +16,10 @@
 
 
 <Command_prompt>:
-  canvas.before:
-    Color:
-      rgb: 0,0,0
-    Rectangle:
-      pos: self.pos
-      size: self.size
   size_hint_y: None
   height: 20
+  markup: True
   text_size: self.size
   font_name: "RobotoMono-Regular"
+  font_size: "15px"