// This Source Code is derived from the version(s) at litesoft.org which are in the Public Domain per: http://litesoft.org/License.txt
package com.wdstechnology.ucci.deviceassist.client.ui;

import com.google.gwt.event.dom.client.MouseMoveEvent;
import com.google.gwt.user.client.*;

public class WidgetMouseHandler {
   public interface MouseClickedListener {
      void mouseClicked();
   }

   public interface Logger {
      void log(String message);
   }

   public static int EVENT_BITS = Event.MOUSEEVENTS;

   private static final State sREGULAR = new State("Regular");

   private static final State sMOUSEOVER = new State("Mouseover");

   private static final State sMOUSEDOWN = new State("Mousedown");

   private static final State sDISABLED = new State("Disabled");

   public static final State[] ALL_STATES = new State[] { sREGULAR, sMOUSEOVER, sMOUSEDOWN, sDISABLED };

   private boolean mMouseOver = false;

   private boolean mMouseDown = false;

   private boolean mDisabled = false;

   protected Element mMouseCtrlElement;

   private MouseClickedListener mListener;

   protected State mCurrentState = null;

   private Element mSavedCaptureElement = null;

   private final Logger mLogger;

   private boolean mLastLogWasMove = false;

   public WidgetMouseHandler(Element pMouseCtrlElement, MouseClickedListener pListener, Logger pLogger) {
      mMouseCtrlElement = pMouseCtrlElement;
      mListener = pListener;
      mLogger = (pLogger != null) ? pLogger : NOOP_LOGGER;
   }

   private State determineNewForm() {
      if (mDisabled) {
         return sDISABLED;
      }
      if (mMouseDown) {
         return sMOUSEDOWN;
      }
      if (mMouseOver) {
         return sMOUSEOVER;
      }
      return sREGULAR;
   }

   public WidgetMouseHandler updateForm() {
      State zNewForm = determineNewForm();
      if (mCurrentState != zNewForm) {
         if (mCurrentState != null) {
            removeCurrentState();

            if (mCurrentState == sMOUSEDOWN) {
               DOM.releaseCapture(mMouseCtrlElement);
               if (mSavedCaptureElement != null) {
                  DOM.setCapture(mSavedCaptureElement);
                  mSavedCaptureElement = null;
               }
            }
         }
         if (zNewForm != sDISABLED) {
            if (zNewForm == sMOUSEDOWN) {
               mSavedCaptureElement = DOM.getCaptureElement();
               if (mSavedCaptureElement != null) {
                  DOM.releaseCapture(mSavedCaptureElement);
               }
               DOM.setCapture(mMouseCtrlElement);
            }
         }
         mCurrentState = zNewForm;
         applyCurrentState();
      }
      return this;
   }

   protected void applyCurrentState() {
      mMouseCtrlElement.addClassName("" + mCurrentState);
   }

   protected void removeCurrentState() {
      mMouseCtrlElement.removeClassName("" + mCurrentState);
   }

   public boolean isEnabled() {
      return !mDisabled;
   }

   public void setEnabled(boolean pEnabled) {
      mDisabled = !pEnabled;
      updateForm();
   }

   public boolean onBrowserEvent(Event pEvent) {
      switch (DOM.eventGetType(pEvent)) {
      case Event.ONMOUSEDOWN:
         eventPreventDefaultAndCancelBubble(pEvent);
         onMouseDown(pEvent);
         break;
      case Event.ONMOUSEUP:
         onMouseUp(pEvent);
         break;
      case Event.ONMOUSEOVER:
         onMouseEnter(pEvent);
         break;
      case Event.ONMOUSEOUT:
         onMouseLeave(pEvent);
         break;
      case Event.ONMOUSEMOVE:
         eventPreventDefaultAndCancelBubble(pEvent);
         onMouseMove(pEvent);
      default:
         return false;
      }
      return !isEnabled();
   }

   protected void onMouseDown(Event pEvent) {
      mouseDown();
   }

   protected void onMouseUp(Event pEvent) {
      mouseUp();
   }

   protected void onMouseEnter(Event pEvent) {
      mouseEnter();
   }

   protected void onMouseLeave(Event pEvent) {
      mouseLeave();
   }

   protected void onMouseMove(Event pEvent) {
      if (!mLastLogWasMove) {
         mLastLogWasMove = true;
         mLogger.log("Move");
      }
      MyMouseMoveEvent zEvent = new MyMouseMoveEvent(pEvent);
      int zRelativeX = zEvent.getRelativeX(mMouseCtrlElement);
      int zOffsetWidth = mMouseCtrlElement.getOffsetWidth();
      int zRelativeY = zEvent.getRelativeY(mMouseCtrlElement);
      int zOffsetHeight = mMouseCtrlElement.getOffsetHeight();
      if (over(zRelativeX, zOffsetWidth) && over(zRelativeY, zOffsetHeight)) {
         if (!mMouseOver) {
            mouseEnter();
         }
      } else {
         if (mMouseOver) {
            mouseLeave();
         }
      }
   }

   private boolean over(int pRelativeAt, int pOffsetSize) {
      return (0 <= pRelativeAt) && (pRelativeAt < pOffsetSize);
   }

   protected void mouseDown() {
      mLastLogWasMove = false;
      mLogger.log("Down");
      mMouseDown = true;
      updateForm();
   }

   protected void mouseUp() {
      mLastLogWasMove = false;
      mLogger.log("Up");
      mMouseDown = false;
      updateForm();
      if (mListener != null) {
         mListener.mouseClicked();
      }
   }

   protected void mouseEnter() {
      mLastLogWasMove = false;
      mLogger.log("Enter");
      mMouseOver = true;
      updateForm();
   }

   protected void mouseLeave() {
      mLastLogWasMove = false;
      mLogger.log("Leave");
      mMouseDown = false;
      mMouseOver = false;
      updateForm();
   }

   public static void eventPreventDefaultAndCancelBubble(Event pEvent) {
      pEvent.preventDefault();
      pEvent.stopPropagation();
   }

   public static class State {
      private String mText;

      public State(String pText) {
         mText = pText;
      }

      @Override
      public String toString() {
         return mText;
      }

      public String getURL(String pURLBaseGifExtentionAssumed) {
         return pURLBaseGifExtentionAssumed + "-" + mText + ".cache.gif";
      }
   }

   protected static class MyMouseMoveEvent extends MouseMoveEvent {
      public MyMouseMoveEvent(Event pEvent) {
         setNativeEvent(pEvent);
      }
   }

   private static final Logger NOOP_LOGGER = new Logger() {
      public void log(String message) {
      }
   };
}