677: Highlights

If you want to display a window containing a drawing, then create subclasses of the ViewManager, TopPane, and GraphPane classes.

then define a createViews method for the view-manager class, such as the following:

createViews 
  | theCalorieViewManager theTopPane theMeterPane | 
  theCalorieViewManager := self. 
  theTopPane := TopPane new. 
  theMeterPane := MeterGraphPane new. 
  "Set up the top pane" 
  theCalorieViewManager addView: theTopPane. 
  theTopPane owner: theCalorieViewManager.  
  theTopPane labelWithoutPrefix: a title string. 
  theTopPane noSmalltalkMenuBar.                                         
  theTopPane framingRatio: a rectangle. 
  "Set up the meter pane" 
  theTopPane addSubpane: theMeterPane. 
  theMeterPane owner: theCalorieViewManager. 
  theMeterPane noScrollBars.                                             
  theMeterPane framingRatio: a rectangle. 
  theMeterPane when: #display perform: #a view-manager method.

then define the method for the view manager named by the when:perform: message:

the view-manager method named by when:perform: thePane 
  thePane a graph pane method.

and then define a drawing method for the graph pane:

the graph pane method 
  ...

If you want to draw lines or display text, then extract a pen from the graph pane by sending a pen message:

the graph pane method 
  | thePen | 
  thePen := self pen. 
  ...

If you want to draw a line, then send the lineFrom:to: message to the pen:

the pen lineFrom: start point to: end point

If you want to display text, then send the displayText:at: or the centerText:at: message to the pen:

the pen displayText: a string at: a point 
the pen centerText: a string at: a point