From d3b2bcce3b52fba5d7996b1add200e5b94a13353 Mon Sep 17 00:00:00 2001
From: mrkubax10 <mrkubax10@onet.pl>
Date: Sun, 3 Mar 2024 17:27:39 +0100
Subject: [PATCH] Implement canvas view moving

---
 canvas.py | 41 ++++++++++++++++++++++++++++++++---------
 1 file changed, 32 insertions(+), 9 deletions(-)

diff --git a/canvas.py b/canvas.py
index 1c27ebd..ccf62f3 100644
--- a/canvas.py
+++ b/canvas.py
@@ -14,8 +14,14 @@ class EditorCanvas(tkinter.Canvas):
         self.current_char_modified=False
         self.width=0
         self.height=0
+        self.prev_mouse_x=0
+        self.prev_mouse_y=0
+        self.view_x=0
+        self.view_y=0
         self.bind("<B1-Motion>",self.handle_draw)
         self.bind("<Button-1>",self.handle_draw)
+        self.bind("<Button-3>",self.handle_move_start)
+        self.bind("<B3-Motion>",self.handle_move)
 
 
     def draw(self):
@@ -23,30 +29,45 @@ class EditorCanvas(tkinter.Canvas):
 
         # draw grid
         for x in range(self.project.char_res[0] + 1):
-            x = x * self.grid_size
-            self.create_line((x,0),(x,self.height),width=1,fill=GRID_COLOR)
+            x = x * self.grid_size+self.view_x
+            self.create_line((x,self.view_y),(x,self.view_y+self.height),width=1,fill=GRID_COLOR)
         for y in range(self.project.char_res[1] + 1):
-            y = y * self.grid_size
-            self.create_line((0,y),(self.width,y),width=1,fill=GRID_COLOR)
+            y = y * self.grid_size+self.view_y
+            self.create_line((self.view_x,y),(self.view_x+self.width,y),width=1,fill=GRID_COLOR)
 
         if self.project.does_char_exist(self.current_char) or self.current_char_modified:
             for i in range(len(self.current_char_pixels)):
-                x=i//self.project.char_res[1]*self.grid_size
-                y=i%self.project.char_res[1]*self.grid_size
+                x=i//self.project.char_res[1]*self.grid_size+self.view_x
+                y=i%self.project.char_res[1]*self.grid_size+self.view_y
                 if self.current_char_pixels[i]>0:
                     self.create_rectangle((x,y),(x+self.grid_size,y+self.grid_size),fill="white")
         else:
-            self.create_line((0,0),(self.width,self.height),width=3,fill="red")
-            self.create_line((self.width,0),(0,self.height),width=3,fill="red")
+            self.create_line((self.view_x,self.view_y),(self.view_x+self.width,self.view_y+self.height),width=3,fill="red")
+            self.create_line((self.view_x+self.width,self.view_y),(self.view_x,self.view_y+self.height),width=3,fill="red")
 
 
     def handle_draw(self,event):
         self.current_char_modified=True
         pixel_pos=self.cursor_pos_to_pixel((event.x,event.y))
+        if not pixel_pos:
+            return
         self.current_char_pixels[pixel_pos[0]*self.project.char_res[1]+pixel_pos[1]]=1
         self.draw()
 
 
+    def handle_move_start(self,event):
+        self.prev_mouse_x=event.x
+        self.prev_mouse_y=event.y
+
+
+    def handle_move(self,event):
+        self.view_x+=event.x-self.prev_mouse_x
+        self.view_y+=event.y-self.prev_mouse_y
+        self.prev_mouse_x=event.x
+        self.prev_mouse_y=event.y
+        self.draw()
+
+
     def load_char(self):
         self.current_char_modified=False
         if not self.project.does_char_exist(self.current_char):
@@ -114,7 +135,9 @@ class EditorCanvas(tkinter.Canvas):
 
 
     def cursor_pos_to_pixel(self,pos):
-        pixel_pos = (int(pos[0] // self.grid_size), int(pos[1] // self.grid_size))
+        pixel_pos = ((pos[0]-self.view_x) // self.grid_size, (pos[1]-self.view_y) // self.grid_size)
+        if pixel_pos[0]<0 or pixel_pos[0]>=self.project.char_res[0] or pixel_pos[1]<0 or pixel_pos[1]>=self.project.char_res[1]:
+            return None
         return pixel_pos