Loads a file into the buffer, return #t if successful, #f otherwise.
The filename used to load the file can be retrieved with get-filename. For a wx:media-edit% instance, the format can be retrieved with get-file-format.
See also set-load-overwrites-styles.
If filename is null, then the internally stored filename will be used; if filename is "" or if the internal name is unset or temporary, then the user will be prompted for a name.
The possible values for format are listed below. A single set of format values are used for loading and saving files:
In a wx:media-edit% instance, the format returned from get-file-format is always one of wx:const-media-ff-std, wx:const-media-ff-text, or wx:const-media-ff-text-force-cr.
If show-errors? is #f, then dialogs reporting save errors are suppressed.