11 Dialog Building Block

Dialog Building Block Toolkit Dialog Building Block Dialog Boxes A Dialog Box on the lisa is a speclal window WhiCh, ,hen displayed, is as .ide as the screen, and hangs down right below the menu bar. D1alog boxes can be used as alternat1ves to menu commands when an application needs to gather more detail from 1ts user than can be conven1ently packaged 1n a menu. A ToolKit application can put up a Dlalog Box any time 1ts .1ndow is active. The D1alog Build1ng Block provides basic structures sufficient to define dialogs, to display them, to specify special behav10ur within them, and to interrogate them. Read No Further The intended audlence for th1s document is current or prospective direct users of the Dialog Building Block. A basic famil1ari ty .i th the 1deas behind the ToolKi t and the CLASCAL language is assumed. ToolKit jargon 15 unavoidable in a document such as thi s. Compalion Doclmentation The primary documentation for the Dialog Building Block consists Of three parts. I l1st them here 1n descending order of 1mportance and authori ty. (8] The source list1ng of the INTERFACE of uD1alog [b) The source lIstings Of the ToolK1t sample programs, USample and UsamD1alog. [c 1 Th1 s document, plus subsequent addenda/errata. How To Do It Simple use of the DIalog Build1ng BloCk involves allocatIng a TDialogwlndow, installing a TOialog, and add1ng dialog components (d1aloglmages) to the d1alog to define its display and behaviour. In a typical dialog Box., an Application and 1ts user aHree that Whatever the user does up In the dialog box Is not for real- until the OK button (or some other action button) 15 pressed. Each standard kind of dialog component carries .i ttl 1t some basic assumptions about mouse- and cursor-behaviour. It is Lisa Tooll1t Dlalog lul1d1ng 110Ck - 71 lIarCl\ 19M - pegt 1 or II Toolkit Dialog Building Block an inherent property of the TCluster component, for example, that one and only one Of its checkboxes is selected at anyone moment. You do not progralll this behaviour--you select It by the very act of Choosing to use a TCluster component. Thus, an application typically defines the for.. and behaviour of a d1alog box by the s1mple act of allocating its components. The real action, whereby the App1icatlon actually does something to 1ts data structures, 1s precipi tated by the user' s pr~sslng a Button in the dialog. The Application 15 able to capture control at button-pushing time In elther of two ways: [a] By redefining TD1alog.ButtonPushed, or [b) by assoclating a command number with a button, and then fielding that command in the Ne.Command methods of Its subclasses of el ther TSelection or Tllndow. Formally, a Dialog is an Object which resides In a Dla10gview, which in turn is installed in some panel of some lindow. Beginning users may think of the Dialog, the Dialogview, and the DialogWindow as confusingly overlapping In function. It Is hoped the explanations below, combined with the streamlined functlonality of the…