Newton Developer Technical Information: Newton Programmer's Guide: 2.1 OS Addendum /

Chapter 2 - Newton Works Draw Application

Summary

Proto

protoDrawTool

 myToolTemplate := {

_proto : protoDrawTool, 
class : classSymbol, // this tool's symbol
icon : pixFamily, //icon for tool bar
createByTapping : Boolean , //create object with pen tap?
createByDragging : Boolean , //create object by dragging bounds?
dragARectangle: Boolean , //create object by dragging a rectangle?
MakeObject: //make a new object
func(left, top, right, bottom, style) ...
SetAttribute: //set an attribute
func(shape, attribute, newValue) ...
MakeDragObject: // make an object to show user when dragging a new obj.
   func(left, top, right, bottom, style) ...
AdjustBounds: // contrain the bounding rect a user drags
func(shape, style, left, top, right, bottom,  constrain) ...
ScaleShape: // scale an object
   func(shape, oldBounds, newBounds) ...
CanvasClickScript : // called when user touches canvas w/your tool
   func(unit)...
ToolClickScript : // called when user taps your tool in the tool bar
   func(unit) ...
ToolBegin : // called before ToolCickScript to set up too
   func() ...
ToolEnd : // called when anothertool is selected, to clean up
   func() ...
...
 }

Data Structures

The Canvas

 canvasView := {

currentDrawStyle : 
AddShape : func(shape, style, nil) ... //add a shape to the canvas
AddShapeToSelection : func(shape) ... //selects a shape
ClearSelection : func() ... //clears selected shapes
SelectAll : func() ... // selects all shapes on the canvas
GetSelectedShapes : func(makeCopy) ... //returns selected shapes
DirtyShape : func(shape) ... //marks as dirty area under a shape
EditGroup : func() ... //groups selection
EditUnGroup : func() ... //ungroups selection
EditCopy : func() ... //copies selection
EditCut : func() ... //cuts selection 
EditPaste : func() ... //pastes clipboard contents
EditDelete : func() ... //deletes selection
EditDuplicate : func() ... //duplicates selection
EditUndo : func() ... //undos last undoable action
...
 }

Draw Application viewDef

 drawApplicationViewDef := {

GetCanvas : func() ... //returns canvas view
GetContents : func() ... //returns contents of canvas
SetContents : func(newShapes) ... //sets contents of canvas
RegPatterns : func(sym, arrayOfPatterns) ... //registers new patterns
UnRegPatterns : func(sym) ... //unregisters new patterns
RegStamps : func(sym, arrayOfStamps) ... //registers new stamps
UnRegStamps : func(sym) ... //unregisters new stamps
RegTool : func(sym, toolTemplate) ... //registers new tool
UnRegTool : func(sym) ... //unregisters new tool
...
 }

---

Subtopics

Proto

protoDrawTool

Data Structures

The Canvas

Draw Application viewDef