Talk:DragSlider

Revision as of 23:09, 29 July 2006

Alternate Version

Below is an edited version of the script that uses coroutines rather than the Update method.

<csharp>// MoveSlider.cs by spaniard 2006-07-19

using UnityEngine; using System.Collections;

public class MoveSlider : MonoBehaviour {

  // This script requires that the sliderBar and sliderWidget have the same transform
  // Positioning is done using pixelOffsets
  public GUITexture sliderBar = null;
  public GUITexture sliderWidget = null;
  public float minValue = 0;
  public float maxValue = 100;
  public float currentValue = 0;
  
  private bool connectedToMouse = false;
  private float originalX = 0;
  private float originalMouseX = 0;
  private float currentX = 0;
  private float halfWidgetWidth = 0;      // used to centre the widget at either end
  
  void Start () {
     halfWidgetWidth = (sliderWidget.pixelInset.xMax - sliderWidget.pixelInset.xMin) / 2;
     currentX = sliderWidget.pixelInset.xMin + halfWidgetWidth;
  }

  void OnMouseDown () {
     connectedToMouse = true;
     originalMouseX = Input.mousePosition.x;
     originalX = sliderWidget.pixelInset.xMin + halfWidgetWidth;
     StartCoroutine("UpdatePosition");
  }
  
  void OnMouseUp () {
     connectedToMouse = false;
  }
  
  IEnumerator UpdatePosition () {
     do {
        // calculate currentX based on mouse position
        currentX = originalX - (originalMouseX - Input.mousePosition.x);
        // translate from the pixel values to the value
        currentValue = (((currentX - sliderBar.pixelInset.xMin) / (sliderBar.pixelInset.xMax - sliderBar.pixelInset.xMin)) * (maxValue - minValue)) + minValue;
        
        // make sure the value isn't out of bounds
        if (currentValue < minValue) {
           currentValue = minValue;
        } else if (currentValue > maxValue) {
           currentValue = maxValue;
        }
        // update where the sliderWidget is drawn from currentValue (in case the value is changed externally)
        currentX = (((currentValue - minValue) / (maxValue - minValue)) * (sliderBar.pixelInset.xMax - sliderBar.pixelInset.xMin)) + sliderBar.pixelInset.xMin;
        sliderWidget.pixelInset = new Rect ((currentX - halfWidgetWidth), sliderWidget.pixelInset.yMin, (currentX + halfWidgetWidth) - (currentX - halfWidgetWidth), sliderWidget.pixelInset.yMax - sliderWidget.pixelInset.yMin);

        yield return new WaitForSeconds(0.05f);
     } while (connectedToMouse);
  }

}</csharp>

I noticed a few errors in this version of the script and fixed them (hopefully):

• StartCoroutine() has a capital S.
• In C#, coroutines must return the type 'IEnumerator'.
• Coroutines must have a yield statement somewhere within their loop or they'll hang the program. I added WaitForSeconds() with a smallish pause, which should be a good tradeoff between responsiveness and efficiency.

I haven't had time to actually run the code, so I can't guarantee that it works, but it should be more right than before. Hope this helps. :) --NCarter 08:42, 20 July 2006 (GMT)

• Thanks for that, I haven't had time to test it yet either, so thanks for the corrections! --spaniard 22:02, 20 July 2006 (GMT)

Update

I'm currently working on a suite of GUI scripts, so this script will be updated along with a series of other parts - checkboxes, text fields, etc. When I'm done, I'll post all of it here. --spaniard 23:09, 29 July 2006 (GMT)