25.1 Planning the Application Design

The first thing you should do when developing any application is formulate a blueprint. That is, you should decide what elements you need, and how those elements fit together to make a whole. There is never only one correct way to create an application, so creating a plan helps you ensure that the way you are approaching the development includes the necessary features and that everything fits together.

The image viewer/slideshow application has four main parts:

Low-resolution preview pane

This portion of the application allows the user to view the low-resolution versions of the images. Each image is loaded into its own viewer that can be resized and moved.

Sequencer

The user can add thumbnails to the sequencer. Dragging and dropping the images into different positions changes the order of the thumbnails.

Sequence viewer

The full images can be played back in the same order as the thumbnails in the sequencer.

Menu

The menu consists of a list box of available images as well as buttons for previewing the images, adding images to the sequencer, and starting the sequence playback.