It inserts a new If/Else clause in the if title. Third, rewrite the existing Choose Menu Item event handler so that it is identical to the new version shown in Listing 1. Because this event handler brings with it a reference to the Preferences window object, add a new statement to the existing Will Open event handler, at the beginning of the if title clause, as follows: set prefsWindow to theWindow We already implemented the Will Open event handler in the previous article. Second, we set the value of the new property so that it refers to the new window object once the Preferences window has been opened for the first time. The PreferencesController.applescript script already has a Properties section, so add this declaration immediately following the declaration of the prefsModelLib property we created in the previous article: property prefsWindow : null In addition, if the property is not null, we must bring the window to the front and make it visible in case it was either closed (i.e., not visible) or it was already open but hidden behind the Doyle Usage Log window.įirst, declare the new prefsWindow property. We will change the value of the property from a null reference to a reference to the new window the first time the window is opened.
We will load the nib file only if the property is still null. We will do something very similar here, declaring a new property, prefsWindow, and setting its initial value to null. The traditional way to do this sort of thing in a Cocoa application is to test whether the Objective-C “instance variable” representing the object is null. We will do this by inserting another If clause in the Choose Menu Item event handler. To fix our bug, we will add some statements to check whether the nib file is already loaded when the user chooses the Preferences command. (An Interface Builder setting could have been used to release the window object’s memory automatically when the window is closed, but this would come at the expense of having to reload it when the window is opened again.) Furthermore, closing the Preferences window does not unload the nib file but only makes the window invisible, so our application could fill memory with multiple instances of the window even if they aren’t visible.
This happens because the nib file is loaded indiscriminately every time the user chooses the Preferences command, even if the nib file was already loaded previously.
Applescript documentation windows#
On the minus side, our first version of the Choose Menu Item event handler may load multiple copies of the nib file, and it may therefore leave multiple Preferences windows open on the screen. This speeds application launching by delaying until later the loading of the Preferences nib file, and it also makes the application’s initial memory footprint smaller.
Applescript documentation plus#
On the plus side, it enhances application performance by loading the Preferences window object “lazily ” that is, only if and when the user requests it. The fact that the Choose Menu Item event handler loads the nib file when the user chooses the Preferences menu command is both a plus and a minus.
A separate Will Open event handler then set the appearance of the checkbox in the Preferences window to match the actual preference value and made the window visible. Recall that the Choose Menu Item event handler did only one thing: it loaded the Preferences.nib nib file that archives information about the Preferences window. In the preferences Controller script, we implemented the Choose Menu Item event handler, connecting it to menu item Application -> Preferences in MainMenu.nib. In the previous article, we created the PreferencesController.applescript file to act as a Model-View-Controller (MVC) “Controller” script coordinating the preferences system’s “Model” (its data, managed by the PreferencesModel.applescript script) with its “View” (the graphical user interface, namely, the Preferences window and its one checkbox). Updating the User Interface for Preferences-Revisited We left until this, the third article in the series, the scripting of the Usage Log itself, including saving it to disk and reading it back.īefore turning to the Usage Log, however, we must fix the bug that we found in Doyle’s preferences system at the end of the previous installment. We also scripted Doyle’s preferences system so that a user could save a preference to show or hide comments in the Usage Log. We began by designing the graphical user interface in Interface Builder, including a Preferences window and a Doyle Usage Log window. In the previous article in this series, we helped Sir Arthur Conan Doyle to start writing an AppleScript document-based application called “Doyle” using AppleScript Studio. Educational Institution and Student Discountsīy Bill Cheeseman, Quechee, VT AppleScript Studio: Implementing a Document-Based Application Saving and Retrieving Documents the Cocoa Way in AppleScript Studio.
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