Collapse ControlP5 DropdownList

Question

I am having issues collapsing a ControlP5 DropdownList object.

I select the item that I want, the arrow points up as if it wanted to collapse....but all of the choices are still there! It never collapses after a selection is made.

I have looked at the isOpen() function and it is telling me that the list is closed. I have also explored the isCollapse() function and it is telling me that the list is already collapsed......

Here is my code for instantiating the object:

    SimilarityChoices = P5Controller.addDropdownList("SimChoices").setPosition((float)(width * .7), 450);
    SimilarityChoices.addItem("Euclidian", 1);
    SimilarityChoices.addItem("Manhattan", 2);
    SimilarityChoices.setValue(2);      
    this.SimilarityChoices.enableCollapse();
    this.SimilarityChoices.setItemHeight(20);
    this.SimilarityChoices.actAsPulldownMenu(true);

If anybody can give me a hint on how to make this work, I'd be much obliged. (And I'm happy to supply more information as well)

Answer 1

You'll notice that the dropdownlist example sketch includes this:

void draw() {
  background(128);
}

which draws over the pixels previously rendered while the list was expanded. I wrote a sketch using your code to illustrate the difference more clearly:

import controlP5.*;

ControlP5 P5Controller;
DropdownList SimilarityChoices;

void setup() {
  size(500, 500);
  P5Controller = new ControlP5(this);
  SimilarityChoices = P5Controller.addDropdownList("SimChoices").setPosition((float)(width * .7), 450);
  SimilarityChoices.addItem("Euclidian", 1);
  SimilarityChoices.addItem("Manhattan", 2);
  SimilarityChoices.setValue(2);      
  this.SimilarityChoices.enableCollapse();
  this.SimilarityChoices.setItemHeight(20);
  this.SimilarityChoices.actAsPulldownMenu(true);
}
void draw() {
  //background(128);
}

Uncommenting the background(128); line makes it behave as expected. I hope that helps! Note that some of the settings you coded in may no longer be necessary.