You'll be able to program in three dimensions once you've created a 3D Squeak System Browser!

Squeak Smalltalk includes a dedicated authoring environment called Alice which you can use to build a 3D landscape or ‘Wonderland’. Alice is also available as an independent authoring tool (more information from www.alice.org). Version 3.7 of Squeak (but not version 3.8) displays a window called ‘Worlds Of Squeak’ when it is first run. If you expand this window then click the window labelled ‘3D’ you will open up an Alice programming tutorial which explains how to make a drumming bunny move around inside a 3D world.

If you are new to Smalltalk and Squeak, you may want to follow our two part Squeak tutorial before going any further. There are more Squeak tutorials on the Why Smalltalk? site: http://www.whysmalltalk.com/tutorials/squeak.htm

Now, without more ado, let's start programming in 3D. Every step is shown in this Flash Tutorial and is documented below.

• Left-click the Squeak workplace.
• Select Open from the popup menu.
• Select Workspace from the next menu.
• In the blank workspace enter this text:
   Wonderland new
• Highlight this text (clicking once just beyond the text will do this).
• Right-click and select ‘Do It’ from the popup menu.
• A new type of workspace appears with a small ‘landscape’ view to the left and a larger Script pane at the right.
• In the Script pane enter this text:
   w makePlaneNamed: ‘testplane’
• Highlight this text.
• Right-click and select ‘Do It’ from the popup menu.
• Notice that a vertical plane has appeared in the small ‘landscape’ picture.
• Try clicking the plane in the landscape view. You can drag it back and forth. If you press the Shift key and click you can move it vertically. If you press Ctrl and click you can rotate it.
• Press the Alt key and left-click in the ‘sky’ area of the landscape. A set of tools will appear around the edge of the picture.
• Click the red ‘menu’ tool (2nd from left at the top).
• From the menu that pops up, click ‘accept drops’.
• Now, in the landscape view, Alt+left-click the white plane to pop up icons around the plane.
• Left-click the red menu icon.
• In the menu, click ‘enable active texture’.
• Alt+left-click the plane again.
• Left-click the red menu icon.
• In the menu, click ‘auto adjust to texture’.
• Left-click an area of the background in the main Squeak window (i.e. the gradient purple-blue colour).
• From the popup menu, select Help.
• From the new menu, select Preferences.
• Click once to fix the Preferences panel in place.
• Delete the text in the Search box and enter the following:
   systemW
• Click Search
• Two results will be displayed with empty checkboxes.
• Click the checkbox by systemWindowEmbedOK
• Click the ‘close’ button in the caption bar to close the Preferences panel.

• Now close the Workspace window (the one containing the text ‘Wonderland new’). Click ‘Yes’ when prompted.
• Make sure the mini landscape view is visible. If necessary, Alt+left-click its ‘sky’ area and use the black ‘pickup’ icon to drag it to a clear area of the desktop.
• Left-click the main Squeak desktop.
• From the menu select Open. Then select Browser.
• A system Browser pops up.
• In the top-left pane select Kernel-Methods.
• In the next pane, select InstructionPrinter.
• In the 4th pane (top-right), select the method jump:if:
• Alt+left-click the system browser to pop up icons around its edges.
• Click the black ‘pickup’ icon (top centre) and drag this directly onto the white plane in the small ‘landscape’ view. Release the mouse button.
• You will see that a mini browser had now been placed onto the plane.
• Alt+left-click the mini-browser. Icons will appear around its edges.
• Left-click the red menu icon.
• From the menu, select ‘disable active texture’
• Alt+left-click the sky area of the landscape.
• Hold-down the Shift key, click the yellow Change Size icon (bottom right) and drag this to increase the size of the landscape window.
• If necessary, click and drag the browser shown in the landscape or rotate it (Ctrl+Left-click and drag) if you happen to be seeing its reverse face at the moment.
• Alt+left-click the browser in the landscape.
• Click the red menu icon.
• From the menu select ‘enable active texture’.
• This causes the browser in the window to change from being a mere picture to a real browser in which the panes and text are active.
• To prove this place your cursor just beyond the end of the code in the bottom pane and left-click to highlight it.
• Press the Delete key to delete the code.
• In its place, enter the following:
   Hello from the 3D browser - we can now write Smalltalk code in 3D.
• Of course this text is not meaningful code so if you select another method in your 3D browser you will be asked if you wish to cancel your changes. Select ‘Yes’ to do so.

If you are new to Squeak, you probably won’t want to keep your work at this stage (it would be all too easy to create some unexpected side effects by writing code in your 3D browser). So when you quit Squeak, don’t save your changes. Alternatively, if you want to carry on playing later on, left-click the desktop background and select Save As. Enter a name such as 3DBrowser.image and click Accept. Then quit Squeak without saving. Squeak will prompt to load a specific image file when you next run it. Your default image won’t have the 3D browser while the one you just saved will have it.

Torsten Bergmann writes a programming blog, The Hitchhiker's Guide To.... at http://astares.blogspot.com/

August 2005