(Redirected from Watcher)

Some Stage monitors.
A Stage monitor, sometimes called a watcher, is a display on the Stage that shows the value of a variable, boolean, or a list. The color behind any number on a Stage monitor is the base color of the block it is corresponding to (in Scratch 1.x only, a Stage monitor can be made any color by Shift-clicking the R and changing the color of the block). They can be shown and hidden by selecting and un-selecting the small box to the left of the block.

In the early developmental stages of Scratch, the Stage monitors were green.[1]

Usage

Monitors are often used for displaying variable data in a project or troubleshooting. For instance, monitors may be used to display a score. For troubleshooting, scripts can become quite complex at times, and having a method by which variables can be analysed at ease can increase productivity toward solving bugs.

Display Types of Monitors

Right-clicking a Stage monitor brings up these options.

There are three types of display for Stage monitors, plus a default display for lists. Most of them can be switched between by right-clicking the monitor and selecting an option.

Variables

Normal Readout

The typical Stage monitor that appears when a variable is created. This shows both the name and the value of the variable.

Large readout

This shows only the value, and in a larger font than the normal readout.

Slider

Setting the slider min and max.

This lets the user manually change the value of a variable inside a range which can be defined by right-clicking the Stage monitor on the project screen and choosing two numbers. Only available for variables.

Built-in Reporters

Built-in reporters (such as the X Position block) have the normal and large readout displays available, but they exclude the slider option since they cannot manually be set to any designated value but are associated with a particular sprite or other value.

Lists

Lists only have one display style, which shows all the elements of the list, and in See Inside mode, can be resized and edited to add, remove, or change items. By right clicking, a list can also be exported or imported.

How to Make Duplicate Monitors

Archive.png This article or section documents something not included in the current version of Scratch (3.0). It is only useful from a historical perspective.
  1. Use the delete button (the scissors on the top of the Scratch program) on the Stage monitor (this deletes the monitor).
  2. Click Edit, then Undelete. Place it anywhere on the Stage.
  3. Click the checkbox that will show and hide the Stage monitor.

Another Stage monitor of the value will appear. Both monitors are functional, and will change accordingly to their value.

Scratch 1.4

In Scratch 1.4, shift-click the R in Scratch at the top left corner of the Scratch program. Then, hold alt and click on the watcher until only the watcher is outlined with options. Click on the green option with boxes on it (top-right corner of outline) and drag the new watcher into place.

How to change the Watcher Color

Archive.png This article or section documents something not included in the current version of Scratch (3.0). It is only useful from a historical perspective.
  • Create a Stage Monitor
  • Shift-Click-R
  • Continually-right-click on the number until the pink text below the watcher reads "WatcherReadoutFrame"
  • Click on the red circle which appears above it.
  • Select "Change color..." and pick a color.

Complete List of Stage Monitors

Motion

Looks

Sensing

Sensors

Sounds

Variables

See Also

References

  1. http://web.archive.org/web/20070116125734/http://weblogs.media.mit.edu/llk/scratch/archives/2006/09/scratch_light.html