The next tool we'll implement is the Scale tool that lets you resize the picture. Like the Move tool, it uses an update sequencing design pattern to implement a modal manipulation tool. However, we'll use a different user scenario, and a different underlying implementation.
The Scale tool will work like this:
- Pressing and holding the button using the finger-thumb pinch gesture will activate the scale manipulation mode. The button will grow enlarged to show it is activated.
- As you continue to hold the pinch gesture and move your gaze to the right, the picture object gets bigger. Move your gaze to the left and the picture shrinks.
- Releasing the pinch gesture (unclicking the button) deactivates Move mode, ...
