1.4 The User Interface

Myron consists of several components, each of which has its own display and provides its own responses to user input. The algebra workspace, the plotter and the book reader are the most frequently used components. No matter which component is active, the previous display can be recovered by touching or clicking the large button with the Myron logo, located at the top left of the display .

When Myron is started, the first component displayed is the algebra workspace. This is where algebraic expressions are entered, transformations are applied and results are presented. It is also where other program components are initiated.

A large number of user-interface controls are visible in the algebra workspace (Figure 1.1). Most of these are buttons that initiate programmed activity when touched or clicked. The buttons are arranged into four groups: the menu bar (across the top), the fast-action bar (below the menu bar), the region to the right of the text-input area (at the bottom) and the region to the right of the text-output area (above the text-input area).

The largest area of the algebra workspace is devoted to the expression region. This is where expressions are displayed and where they interact by touching and dragging.

At the right extreme of the menu bar, a button with the icon produces a drop-down menu. Some items on the menu produced additional menus. On devices with small screens, the menu icon might be a hardware button.

Some buttons and menu items hand control of the display over to other program components. As mentioned above, these have their own user-interface controls. Each component is described in its own section of this guide.

The desktop version of Myron (Figure 1.2) has a similar appearance, but note some additional buttons to the right of the text-input and text-output areas. These control features of the desktop version that are different from the Android version. They are described in §2.11.3.

The Android and desktop displays use touch and mouse inputs in consistent ways.

Android	Desktop	Action
touch	click	select
touch and move	move with left button down	drag
touch and hold	left button down and hold	long press
two-finger pinch	scroll wheel forward with left button down	zoom in
two-finger spread	scroll wheel back with left button down	zoom out