A Glimpse example demonstrating dragging IconPainter icons

ClickDragExample.java

import java.io.IOException;
import java.util.Collection;

import com.metsci.glimpse.axis.Axis1D;
import com.metsci.glimpse.axis.Axis2D;
import com.metsci.glimpse.event.mouse.GlimpseMouseAdapter;
import com.metsci.glimpse.event.mouse.GlimpseMouseEvent;
import com.metsci.glimpse.event.mouse.GlimpseMouseMotionListener;
import com.metsci.glimpse.examples.Example;
import com.metsci.glimpse.examples.basic.HeatMapExample;
import com.metsci.glimpse.examples.icon.TextureAtlasExample;
import com.metsci.glimpse.layout.GlimpseLayoutProvider;
import com.metsci.glimpse.plot.ColorAxisPlot2D;
import com.metsci.glimpse.support.atlas.TextureAtlas;
import com.metsci.glimpse.support.atlas.painter.IconPainter;
import com.metsci.glimpse.support.atlas.painter.IconPainter.PickResult;
import com.metsci.glimpse.support.selection.SpatialSelectionListener;

public class ClickDragExample implements GlimpseLayoutProvider
{
    public static void main( String[] args ) throws Exception
    {
        example = Example.showWithSwing( new ClickDragExample( ) );
    }

    protected static Example example;

    protected boolean dragInProgress;
    protected PickResult lastPickResult;

    @Override
    public ColorAxisPlot2D getLayout( ) throws IOException
    {
        // start with HeatMapExample, which uses a ShadedTexturePainter
        final ColorAxisPlot2D plot = new HeatMapExample( ).getLayout( );

        // don't have any absolute minimum constraints on the x axis
        plot.getAxisY( ).setAbsoluteMin( -Double.MAX_VALUE );
        plot.getAxisY( ).validate( );

        // create a texture atlas (contains icons to draw efficiently to the screen)
        final TextureAtlas atlas = new TextureAtlas( 256, 256 );
        // load the atlas with some example images
        TextureAtlasExample.loadTextureAtlas( atlas );

        // create a painter for drawing icons
        final IconPainter iconPainter = new IconPainter( );
        // enable picking on the IconPainter for the plots center drawing area
        // this will allow the SpatialSelectionListener added later to function
        iconPainter.setPickingEnabled( plot.getLayoutCenter( ) );

        // add the painter to the plot
        plot.addPainter( iconPainter );

        // tell the painter to use the texture atlas we created
        // for the set of icons we arbitrarily designate "group1"
        iconPainter.addIconGroup( "group1", atlas );
        iconPainter.addIconGroup( "group2", atlas );

        // add the icon with id "glimpse" at position ( 0.0, 0.0 ) in axis coordinates
        // the icon "glimpse" was loaded/defined by the TextureAtlasExample.loadTextureAtlas( ) call 
        iconPainter.addIcon( "group1", "glimpse", 0.0f, 0.0f, 0.0f, 0.4f );
        iconPainter.addIcon( "group2", "glimpse", 100.0f, 100.0f, 0.0f, 0.4f );

        // add a listener which will report the icon under the mouse and save it to a field
        iconPainter.addSpatialSelectionListener( new SpatialSelectionListener<PickResult>( )
        {
            @Override
            public void selectionChanged( Collection<PickResult> newSelectedIcons )
            {
                if ( newSelectedIcons.isEmpty( ) )
                {
                    if ( !dragInProgress ) lastPickResult = null;
                }
                else
                {
                    lastPickResult = newSelectedIcons.iterator( ).next( );
                }
            }
        } );

        // add a listener which reports when the mouse moves
        // if the mouse button is held down under an icon, the icon is moved
        // so that it appears as if it is being dragged by the mouse
        plot.addGlimpseMouseMotionListener( new GlimpseMouseMotionListener( )
        {
            @Override
            public void mouseMoved( final GlimpseMouseEvent e )
            {
                // if a button is being held down and the mouse is over an icon
                // then drag the icon instead of translating the plot
                if ( e.isAnyButtonDown( ) && lastPickResult != null )
                {
                    // do this on the repaint thread to avoid the possibility
                    // of the icon appearing to flicker
                    example.getManager( ).asyncExec( new Runnable( )
                    {
                        @Override
                        public void run( )
                        {
                            Axis2D axis = e.getAxis2D( );

                            // get the coordinates of the mouse event in axis coordinates ( e.getX( ) returns pixel coordinates )
                            double x = axis.getAxisX( ).screenPixelToValue( e.getX( ) );
                            double y = axis.getAxisY( ).screenPixelToValue( axis.getAxisY( ).getSizePixels( ) - e.getY( ) );

                            // icon painter does not currently provide a way to change the position of an icon
                            // so we have to remove the group and recreate it
                            iconPainter.removeIconGroup( lastPickResult.getGroupId( ) );
                            iconPainter.addIconGroup( lastPickResult.getGroupId( ), atlas );
                            iconPainter.addIcon( lastPickResult.getGroupId( ), lastPickResult.getIconId( ), ( float ) x, ( float ) y, 0.0f, 0.4f );
                        }
                    } );
                }
            }
        } );

        // add another mouse listener which reports when the mouse button is pressed
        // this is used to lock the axes if the mouse is under an icon
        plot.addGlimpseMouseListener( new GlimpseMouseAdapter( )
        {
            @Override
            public void mousePressed( GlimpseMouseEvent event )
            {
                // if an icon is selected, lock the axes so that the icon can
                // be dragged around without translating the plot
                if ( lastPickResult != null )
                {
                    dragInProgress = true;
                    setAxisLocked( plot.getAxis( ), true );
                }
            }

            @Override
            public void mouseReleased( GlimpseMouseEvent event )
            {
                dragInProgress = false;
                setAxisLocked( plot.getAxis( ), false );
            }
        } );

        return plot;
    }

    // helper function to lock / unlock an Axis2D
    protected void setAxisLocked( Axis2D axis, boolean locked )
    {
        if ( locked )
        {
            Axis1D axisX = axis.getAxisX( );
            axisX.lockMax( axisX.getMax( ) );
            axisX.lockMin( axisX.getMin( ) );

            Axis1D axisY = axis.getAxisY( );
            axisY.lockMax( axisY.getMax( ) );
            axisY.lockMin( axisY.getMin( ) );
        }
        else
        {
            Axis1D axisX = axis.getAxisX( );
            axisX.unlockMax( );
            axisX.unlockMin( );

            Axis1D axisY = axis.getAxisY( );
            axisY.unlockMax( );
            axisY.unlockMin( );
        }

        axis.getAxisX( ).validate( );
        axis.getAxisY( ).validate( );
    }
}