/*
 * Smart GWT (GWT for SmartClient)
 * Copyright 2008 and beyond, Isomorphic Software, Inc.
 *
 * Smart GWT is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License version 3
 * as published by the Free Software Foundation.  Smart GWT is also
 * available under typical commercial license terms - see
 * http://smartclient.com/license
 *
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 */

import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.Map;

import com.smartgwt.client.types.Cursor;
import com.smartgwt.client.types.LineCap;
import com.smartgwt.client.types.LinePattern;
import com.smartgwt.client.widgets.Canvas;
import com.smartgwt.client.widgets.Label;
import com.smartgwt.client.widgets.drawing.DrawCurve;
import com.smartgwt.client.widgets.drawing.DrawItem;
import com.smartgwt.client.widgets.drawing.DrawLabel;
import com.smartgwt.client.widgets.drawing.DrawLine;
import com.smartgwt.client.widgets.drawing.DrawOval;
import com.smartgwt.client.widgets.drawing.DrawPane;
import com.smartgwt.client.widgets.drawing.DrawTriangle;
import com.smartgwt.client.widgets.drawing.Point;
import com.smartgwt.client.widgets.events.ClickEvent;
import com.smartgwt.client.widgets.events.ClickHandler;
import com.smartgwt.client.widgets.form.DynamicForm;
import com.smartgwt.client.widgets.form.fields.ToggleItem;
import com.smartgwt.client.widgets.form.fields.events.ChangedEvent;
import com.smartgwt.client.widgets.form.fields.events.ChangedHandler;
import com.smartgwt.client.widgets.layout.VStack;

import com.google.gwt.core.client.EntryPoint;

public class SvgHitDetectionSample implements EntryPoint {

// Center point coordinates
    private final int centerX = 300;
    private final int centerY = 250;

// Instance variables for shapes and UI
 private DrawItem[] allShapes;
 private Map<String, String> shapeNames;
 private Map<String, String> originalColors;
 private Map<String, Integer> originalWidths;
 private boolean usePreciseDetection = true;
 private DrawLine scanLine;
 private Label statusLabel;
 private DrawPane mainPane;

public void onModuleLoad() {
 // Map to store custom shape names (since DrawItem doesn't have shapeName property)
 shapeNames = new HashMap<String, String>();
 originalColors = new HashMap<String, String>();
 originalWidths = new HashMap<String, Integer>();

mainPane = new DrawPane();
        mainPane.setID("mainPane");
        mainPane.setWidth(600);
        mainPane.setHeight(500);
        mainPane.setShowEdges(true);
        mainPane.setCursor(Cursor.CROSSHAIR);
        mainPane.setCanHover(true);
        mainPane.setPrompt("Click somewhere to see intersections");

// Large arc - opens downward
        DrawCurve arc1 = new DrawCurve();
        arc1.setDrawPane(mainPane);
        arc1.setStartPoint(new Point(80, 350));
        arc1.setEndPoint(new Point(200, 350));
        arc1.setControlPoint1(new Point(80, 480));
        arc1.setControlPoint2(new Point(200, 480));
        arc1.setLineColor("#3498DB");
        arc1.setLineWidth(6);
        arc1.setLineCap(LineCap.ROUND);
        registerShape(arc1, "Blue Arc");
        arc1.draw();

// Arc on the right side
        DrawCurve arc2 = new DrawCurve();
        arc2.setDrawPane(mainPane);
        arc2.setStartPoint(new Point(550, 100));
        arc2.setEndPoint(new Point(450, 250));
        arc2.setControlPoint1(new Point(450, 100));
        arc2.setControlPoint2(new Point(450, 175));
        arc2.setLineColor("#27AE60");
        arc2.setLineWidth(6);
        arc2.setLineCap(LineCap.ROUND);
        registerShape(arc2, "Green Arc");
        arc2.draw();

// S-Curve
        DrawCurve sCurve = new DrawCurve();
        sCurve.setDrawPane(mainPane);
        sCurve.setStartPoint(new Point(241, 30));
        sCurve.setEndPoint(new Point(238, 252));
        sCurve.setControlPoint1(new Point(136, 55));
        sCurve.setControlPoint2(new Point(234, 194));
        sCurve.setLineColor("#E74C3C");
        sCurve.setLineWidth(6);
        sCurve.setLineCap(LineCap.ROUND);
        registerShape(sCurve, "Red Curve");
        sCurve.draw();

// Oval
        DrawOval oval1 = new DrawOval();
        oval1.setDrawPane(mainPane);
        oval1.setLeft(420);
        oval1.setTop(320);
        oval1.setWidth(140);
        oval1.setHeight(80);
        oval1.setLineColor("#8E44AD");
        oval1.setLineWidth(4);
        registerShape(oval1, "Purple Oval");
        oval1.draw();

// Triangle
        DrawTriangle triangle1 = new DrawTriangle();
        triangle1.setDrawPane(mainPane);
        triangle1.setPoints(new Point(50, 280), new Point(150, 280), new Point(100, 180));
        triangle1.setLineColor("#E67E22");
        triangle1.setLineWidth(4);
        registerShape(triangle1, "Orange Triangle");
        triangle1.draw();

// Cyan curve at bottom
        DrawCurve arc3 = new DrawCurve();
        arc3.setDrawPane(mainPane);
        arc3.setStartPoint(new Point(350, 450));
        arc3.setEndPoint(new Point(550, 450));
        arc3.setControlPoint1(new Point(400, 350));
        arc3.setControlPoint2(new Point(500, 350));
        arc3.setLineColor("#00BFFF");
        arc3.setLineWidth(6);
        arc3.setLineCap(LineCap.ROUND);
        registerShape(arc3, "Cyan Curve");
        arc3.draw();

allShapes = new DrawItem[] { arc1, arc2, sCurve, oval1, triangle1, arc3 };

// Center point marker
        DrawOval centerMarker = new DrawOval();
        centerMarker.setDrawPane(mainPane);
        centerMarker.setLeft(centerX - 10);
        centerMarker.setTop(centerY - 10);
        centerMarker.setWidth(20);
        centerMarker.setHeight(20);
        centerMarker.setFillColor("#000000");
        centerMarker.setLineColor("#FFFFFF");
        centerMarker.setLineWidth(3);
        centerMarker.draw();

// Center label
        DrawLabel centerLabel = new DrawLabel();
        centerLabel.setDrawPane(mainPane);
        centerLabel.setLeft(centerX + 18);
        centerLabel.setTop(centerY - 8);
        centerLabel.setContents("Center");
        centerLabel.setFontSize(12);
        centerLabel.setFontWeight("bold");
        centerLabel.setLineColor("#000000");
        centerLabel.draw();

// Scan line from center to click point
        scanLine = new DrawLine();
        scanLine.setDrawPane(mainPane);
        scanLine.setStartPoint(new Point(centerX, centerY));
        scanLine.setEndPoint(new Point(centerX, centerY));
        scanLine.setLineColor("#FF00FF");
        scanLine.setLineWidth(3);
        scanLine.setLinePattern(LinePattern.DASH);
        scanLine.draw();

// Handle clicks on the pane
        mainPane.addClickHandler(new ClickHandler() {
            @Override
            public void onClick(ClickEvent event) {
                int x = mainPane.getOffsetX();
                int y = mainPane.getOffsetY();

// Disable the one-time hover hint after first click
                if (mainPane.getPrompt() != null) {
                    mainPane.setPrompt(null);
                }

// Update the scan line and detect intersections
                scanLine.setEndPoint(new Point(x, y));
                detectIntersections(x, y);
            }
        });

// Status label
 statusLabel = new Label();
 statusLabel.setWidth(600);
 statusLabel.setHeight(30);
 statusLabel.setContents("Line intersects: (click anywhere to draw a line from center)");
 statusLabel.setPadding(5);

// Toggle for precise hit detection
        final ToggleItem toggleItem = new ToggleItem("preciseHitDetection", "Use precise geometric hit detection");
        toggleItem.setWrapTitle(false);
        toggleItem.setDefaultValue(true);
        toggleItem.addChangedHandler(new ChangedHandler() {
            @Override
            public void onChanged(ChangedEvent event) {
                usePreciseDetection = (Boolean) event.getValue();
                // Re-run detection with existing line position
                Point endPoint = scanLine.getEndPoint();
                if (endPoint.getX() != centerX || endPoint.getY() != centerY) {
                    detectIntersections(endPoint.getX(), endPoint.getY());
                } else {
                    resetShapes();
                }
            }
        });

DynamicForm toggleForm = new DynamicForm();
        toggleForm.setID("hitDetectionToggleForm");
        toggleForm.setWidth(400);
        toggleForm.setItems(toggleItem);

VStack layout = new VStack();
        layout.setWidth100();
        layout.setMembersMargin(10);
        layout.setMembers(statusLabel, mainPane, toggleForm);

layout.draw();
    }

private void registerShape(DrawItem shape, String name) {
        String id = shape.getID();
        shapeNames.put(id, name);
        originalColors.put(id, shape.getLineColor());
        originalWidths.put(id, shape.getLineWidth());
    }

private String getShapeName(DrawItem shape) {
        return shapeNames.get(shape.getID());
    }

private void resetShapes() {
        for (DrawItem shape : allShapes) {
            String id = shape.getID();
            shape.setLineColor(originalColors.get(id));
            shape.setLineWidth(originalWidths.get(id));
        }
    }

private boolean isPointInBounds(DrawItem shape, int x, int y) {
        return shape.isInBounds(x, y);
    }

private void detectIntersections(int endX, int endY) {
        resetShapes();

// Temporarily hide the scanLine so it doesn't block hit detection
        scanLine.hide();

Map<String, DrawItem> hitShapes = new LinkedHashMap<String, DrawItem>();
 int numSamples = 100;

for (int i = 0; i <= numSamples; i++) {
 double t = (double) i / numSamples;
 int localX = (int) (centerX + t * (endX - centerX));
 int localY = (int) (centerY + t * (endY - centerY));

for (DrawItem shape : allShapes) {
                String name = getShapeName(shape);
                if (hitShapes.containsKey(name)) continue;

boolean hit;
                if (usePreciseDetection) {
                    hit = shape.isPointInPath(localX, localY);
                } else {
                    hit = isPointInBounds(shape, localX, localY);
                }

if (hit) {
                    hitShapes.put(name, shape);
                }
            }
        }

// Show the scanLine again
        scanLine.show();

// Highlight hit shapes
 StringBuilder hitNames = new StringBuilder();
 for (Map.Entry<String, DrawItem> entry : hitShapes.entrySet()) {
 DrawItem shape = entry.getValue();
 shape.setLineColor("#FFFF00");
 shape.setLineWidth(10);
 if (hitNames.length() > 0) hitNames.append(", ");
 hitNames.append(entry.getKey());
 }

// Update status
 if (hitNames.length() > 0) {
 statusLabel.setContents("Line intersects: " + hitNames.toString());
 } else {
 statusLabel.setContents("Line intersects: (no shapes)");
 }
 }

}