Update of /project/mcclim/cvsroot/mcclim/Doc/Guided-Tour In directory clnet:/tmp/cvs-serv23388
Modified Files: guided-tour.tex Log Message: Minor wording changes and typo fixes to the middle of the document.
--- /project/mcclim/cvsroot/mcclim/Doc/Guided-Tour/guided-tour.tex 2006/03/16 15:50:20 1.3 +++ /project/mcclim/cvsroot/mcclim/Doc/Guided-Tour/guided-tour.tex 2006/03/21 15:00:24 1.4 @@ -991,7 +991,7 @@
\subsection{A simple drawing application}
-We move on to a simple drawing application that draws +We move on to a simple application that draws lines and inserts text interactively. Our simple drawing program defines commands for various drawing operations and binds specific input events to these commands. @@ -1005,6 +1005,11 @@ multiple layouts with this option. We define two simple layouts, \code{default-layout} and \code{alternative}.
+% I was confused by the discussion of layouts here. Looking at Figure +% 4, I do not see an alternative layout, and the default-default in +% the listing looks odd to me. Is this the remainder of a discussion +% that was deleted or an extension yet to be written? [2006/03/19:rpg] + \begin{figure*}[t] \lstset{style=framestyle} \lstinputlisting{draw-frame-commands} @@ -1048,8 +1053,18 @@ static user interfaces use this mixin. Note that \mcclim{} is sensitive to the order of the superclasses.\footnote{All stream classes like \class{standard-extended-input-stream} must be listed before -\class{basic-pane}. Otherwise, there are no stream handling facilities -available.} +\class{basic-pane}. Otherwise, no stream handling facilities +will be available.} + +% The above footnote refers to what looks like a very big potential +% ``gotcha'' for the beginning McCLIM programmer. Suggestion: promote +% this out of the footnote into body text as a main body paragraph +% here. That paragraph should explain (1) why is it that putting +% basic-pane before standard-extended-input-stream will cause stream +% handling facilities to be crushed and (2) what exactly are the +% implications of not having stream handling facilities. The phrase +% ``stream handling'' hasn't been defined, and it's not obvious what +% these facilities are. [2006/03/19:rpg]
For \class{draw-pane}, the \method{handle-repaint} method shown in \figurename~\ref{fig-draw-handlerepaint} is straightforward. It @@ -1085,41 +1100,61 @@ conveniently. The interactor pane can be used to invoke one of three commands, either by typing the complete command including all its parameters or by typing only the command name, then a dialog queries -the user for the missing command argument. Clicking on the menu bar -entries is also possible. Also in this case, the user is queried for -the missing arguments. +the user for the missing command argument(s). Clicking on the menu bar +entries is another way to invoke commands. When commands are invoked +through the menu bar, the user will be queried for the missing +argument(s) in the same way as if a command had been typed into the +interactor pane. +% also possible. Also in this case, the user is queried for +% the missing arguments.
But drawing by typing coordinates is not convenient. Therefore, we attach these commands to other user interactions. Figure -\ref{fig-draw-interfacing} defines input methods for pointer button -presses as well as key presses on the draw pane. Both handlers invoke -the respective tracking function that uses \macro{tracking-pointer} to +\ref{fig-draw-interfacing} defines input methods (methods for +\code{handle-event}) for pointer button +presses as well as key presses on the draw pane. +Each handler invokes a tracking function (\code{track-line-drawing} and +\code{track-text-drawing}) that uses \macro{tracking-pointer} to bypass the regular input distribution channels and to dispatch events to user defined handlers. - -For \class{pointer-button-press-event}, the input loop manages a -``rubber-banding'' line. The \keyword{:pointer-motion} is invoked +% old text: [2006/03/19:rpg] +% Both handlers invoke +% the respective tracking function that uses \macro{tracking-pointer} to +% bypass the regular input distribution channels and to dispatch events +% to user defined handlers. + +For \class{pointer-button-press-event}, which is used to draw lines, +the input loop manages a +``rubber-banding'' line. % +% what is pointer-motion here? Is it an event? And it's not really +% the event that's invoked, to be absolutely clear. The event is +% signaled, and the tracking-pointer macro provides a handler for that +% event. So it is the code associated with :pointer-motion that is +% invoked... I wasn't confident enough in my understanding of the +% precise organization of the (Mc)CLIM architecture to venture a +% rewrite, but there should be a clarification here. [2006/03/19:rpg] +The \keyword{:pointer-motion} is invoked whenever the mouse pointer is moved by the user. The code attached to -\keyword{:pointer-motion} clears line already drawn and draws a new +\keyword{:pointer-motion} clears the previously-drawn line and draws a new line with the new pointer position. It can easily undraw the old line by the using the special ink \constant{+flipping-ink+}. When the user confirms the line by releasing the pointer button, a command to the application is synthesized via \method{execute-frame-command} supplying all required parameters.
-Similarly, we provide such an input facility for text input. Whenever +We provide a similar input facility for text input. Whenever the user hits a key in the draw-pane, the respective \method{handle-event} calls \method{track-text-drawing} which attaches -the character entered to the mouse pointer. Similarly to the -rubber-banding line, the user can move the around this character while +the character entered to the mouse pointer. As with the +rubber-banding line, the user can move the displayed string around while he is free to append additional string characters by additional key presses. He can confirm the text position with a mouse click causing a -command to be dispatched to the application frame adding the text to +command to be dispatched to the application frame that will add the text to the application frame permanently.
As each of these methods invoke \code{execute-frame-command} passing -in a special command invocation form, this naturally leads to code -separation of how a command is invoked (menu-bar click, click on +in a special command invocation form, this naturally leads to a +separation between the code that specifies how a command is invoked (menu-bar click, click on draw-pane or typing in the interactor pane) and the code for command execution (code bodies of \method{define-command}).