Android How to Program, 3/e

5.11 EraseImageDialogFragment Class

Class EraseImageDialogFragment (Fig. 5.49) extends DialogFragment to create an AlertDialog that confirms whether the user really wants to erase the entire image. The class is similar to class ColorDialogFragment and LineWidthDialogFragment, so we discuss only method onCreateDialog (lines 15–35) here. The method creates an AlertDialog with Erase Image and Cancel button. Lines 24–30 configure the Erase Image button as the positive button—when the user touches this, line 27 in the button’s listener calls the DoodleView’s clear method to erase the image. Line 33 configures Cancel as the negative button—when the user touches this, the dialog is dismissed. In this case, we use the predefined Android String resource ...