// This Source Code is in the Public Domain per: http://unlicense.org
package org.litesoft.GWT.client.widgets.nonpublic;

import org.litesoft.GWT.client.widgets.nonpublic.external.*;

import com.google.gwt.user.client.ui.*;

public abstract class AbstractSizeableVerticalSplitPairPanel extends AbstractSizeableVerticalPanel {
    private VerticalSplitterDragger mDragger;

    @Override
    protected void initialize() {
        super.initialize();
        LLstretchableVertically();
    }

    public AbstractSizeableVerticalSplitPairPanel add( Widget pTopWidget, Widget pBottomWidget ) {
        add( pTopWidget );
        add( pBottomWidget );
        return this;
    }

    @Override
    protected boolean aboutToAdopt( Widget pWidget, int pBeforeIndex ) {
        if ( pWidget instanceof Splitter ) {
            throw new IllegalArgumentException( "Attempt to add Splitter directly" );
        }
        if ( !getSizeableWidget( pWidget ).getHeightHelper().isStretchable() ) {
            throw new IllegalArgumentException( "Attempt to add widget to Vertical Split Pair Panel that does NOT support Vertical Stretchability" );
        }
        if ( !isOur( pWidget ) && (getWidgetCount() == 3) ) {
            throw new IllegalArgumentException( "Vertical Split Pair Panel only supports TWO Vertical Stretchables" );
        }
        return super.aboutToAdopt( pWidget, pBeforeIndex );
    }

    @Override
    protected void justAdopted( Widget pWidget, int pWidgetIndex ) {
        super.justAdopted( pWidget, pWidgetIndex );

        // Since we only support 2 real widgets, they could be disordered in regards to the splitter
        dropSplitters();
        if ( getWidgetCount() == 2 ) {
            LLadopt( createSplitter( 1 ), 1 );
        }
    }

    @Override
    protected void justDisowned( Widget pWidget, int pWidgetIndex ) {
        super.justDisowned( pWidget, pWidgetIndex );

        // Since we only support 2 real widgets, any disowned should remove the splitter
        dropSplitters();
    }

    private void dropSplitters() {
        for ( int i = getWidgetCount(); --i >= 0; ) {
            Widget widget = getWidget( i );
            if ( widget instanceof Splitter ) {
                LLdisown( widget, i );
            }
        }
    }

    protected Widget createSplitter( int pIndex ) {
        Splitter result = new Splitter( "litesoft-SplitterForVerticalPair" );
        result.stretchableHorizontally();
        mDragger = new VerticalSplitterDragger( this, pIndex );
        result.addController( new DragController( new MousePerformanceFilter( new MouseDragHandler( mDragger ) ) ) );
        return result;
    }

    private class VerticalSplitterDragger extends AbstractSplitterDragger {
        public VerticalSplitterDragger( AbstractSizeableOneDimensionalPanel panel, int pIndex ) {
            super( panel, pIndex );
        }

        @Override
        protected boolean dragBy( int pDeltaX, int pDeltaY ) {
            return adjustSizesBy( getSizeableAt( mIndex - 1 ).getHeightHelper(), //
                                  getSizeableAt( mIndex + 1 ).getHeightHelper(), //
                                  pDeltaY );
        }
    }

    @Override
    public void setWidth( String width ) {
        super.setWidth( width ); // for stacktrace Debugging
    }

    @Override
    public void setHeight( String height ) {
        super.setHeight( height ); // for stacktrace Debugging
    }

    private boolean mFavorFirstWidget;

    protected void setFavorFirstWidget() {
        mFavorFirstWidget = true;
    }

    public boolean setFirstWidgetHeight( int pPixels ) {
        if ( (pPixels > 20) && anyChildren() ) {
            int zDimension = getHeightHelper().getDimension();
            if ( (zDimension > 20) && (zDimension != pPixels) ) {
                mDragger.dragBy( 0, pPixels - zDimension );
                return true;
            }
        }
        return false;
    }

    @Override
    protected void distributeToChildrenChangedHeight() {
        if ( anyChildren() ) {
            getHelper().distributeDimensionToChild( this, getHeightHelper(), mFavorFirstWidget ? getFirstWidget() : getLastWidget() );
        }
    }
}