Showing and Hiding Objects


I created a simple GeoGebra worksheet with a circle and several "spokes" attached to the middle.  Using the Checkbox tool we can show/hide the circle and the spokes.  Here is the file: Tutorial-8-1.ggb.
Sorry, the GeoGebra Applet could not be started. Please make sure that Java 1.4.2 (or later) is installed and active in your browser (Click here to install Java now)
But what I'd really like is to make the ability to show/hide the spokes dependent on whether or not the circle is showing, like the one to the right.
Here is the file: Tutorial-8-2.ggb.
Sorry, the GeoGebra Applet could not be started. Please make sure that Java 1.4.2 (or later) is installed and active in your browser (Click here to install Java now)
Here's the idea: once I've created two checkboxes, I rename the boolean values  tfWheel  and  tfSpokes  (I prefix it with tf to remind me that its only values are true and false).

In Object Properties, I select tfSpokes, and under the Advanced tab, in the "Condition to Show Object" area I enter  tfWheel.

Now, the tfSpokes checkbox only appears whenever tfWheel is true (that is, then the checkbox is checked).



The spokes consist of 5 segments and 5 points.  Next I click the word "Segment" to select all the segments, then under "Condition to Show Object" I type
    tfSpokes && tfWheel

When I hit enter, the && gets replaced with the logical "and" symbol, as seen to the right.

I similarly change the 5 points that are at the end of each spoke.

More on logical operations here.

Try the applet to the right.
Here is the file: Tutorial-8-3.ggb.
Sorry, the GeoGebra Applet could not be started. Please make sure that Java 1.4.2 (or later) is installed and active in your browser (Click here to install Java now)
I created three text areas and named them  txtInstructions,  txtWarm, and  txtHot.

To make txtWarm appear I enter
    Distance[ A, (6, 3) ] ≤ 1.5
in the "Condition to Show Object" box.

To enter the less-than-or-equal sign, you can type Alt-<, or you can select it from the drop down box to the right of the text field.

In this last example, I use a slider to control when objects are shown.
Here is the file: Tutorial-8-simson.ggb.
  Sorry, the GeoGebra Applet could not be started. Please make sure that Java 1.4.2 (or later) is installed and active in your browser (Click here to install Java now)

Back to Home Tutorial Page