adjust zoom level

command_prompt.py

@@ -323,6 +323,8 @@ class Command_prompt(Label):
         elif argv[1]=="grid":
             self.run_set_grid(argv)
             return
+        elif argv[1]=="zoom":
+            self.run_set_zoom(argv)
         else:
             self.message="error: unrecognized command '"+argv[1]+"'"
             return
@@ -383,6 +385,22 @@ class Command_prompt(Label):
                 return
             self.app.painter.set_grid(mesh)
 
+    # set zoom level (changes size of elements)
+    def run_set_zoom(self,argv):
+        if len(argv)==2:
+            self.message="error: missing argument in 'set zoom'"
+            return
+        else:
+            try:
+                zoom_level=float(argv[2])
+            except:
+                self.message="error: unrecognized argument '"+argv[2]+"' -- usage 'set zoom <zoom_level>'"
+                return
+            if zoom_level<0:
+                self.message="error: zoom level cannot be negative: '"+argv[2]+"'"
+                return
+            self.app.painter.set_zoom(zoom_level)
+            
 
 
     # write to file

painter.py

@@ -110,6 +110,17 @@ class Painter(Widget):
                         particle.grid=-particle.grid
                 self.draw()
 
+            # zoom
+            elif keycode[1]=="+":
+                # increment by 10%
+                self.set_zoom(Square_element.size/50*1.1)
+            elif keycode[1]=="-":
+                # decrease by 10%
+                self.set_zoom(Square_element.size/50*0.9)
+            elif keycode[1]=="=":
+                # reset
+                self.set_zoom(1)
+
     def on_key_up(self, keyboard, keycode):
         if keycode[1]=="shift":
             if 's' in self.modifiers:
@@ -414,6 +425,11 @@ class Painter(Widget):
         ff.close()
         self.draw()
 
+    # set zoom level
+    def set_zoom(self,level):
+        Square_element.size=level*50
+        self.draw()
+
 
 # global variables (used like precompiler variables)
 CROSS_INDEX=1