Helper class to capture mouse movements on the canvas for CanvasOverlay class.

java/com.sap.sailing.gwt.ui/src/main/java/com/sap/sailing/gwt/ui/simulator/util/WindFieldMouseMoveHandler.java

@@ -0,0 +1,72 @@
+/**
+ * 
+ */
+package com.sap.sailing.gwt.ui.simulator.util;
+
+import java.util.Map;
+
+import com.google.gwt.canvas.client.Canvas;
+import com.google.gwt.canvas.dom.client.Context2d;
+import com.google.gwt.canvas.dom.client.ImageData;
+import com.google.gwt.event.dom.client.MouseMoveEvent;
+import com.google.gwt.event.dom.client.MouseMoveHandler;
+import com.sap.sailing.gwt.ui.shared.WindDTO;
+
+/**
+ * To handle MouseMoveEvent to display tool tips around WindDTO objects in a wind field
+ * 
+ * @author Nidhi Sawhney(D054070)
+ * 
+ */
+public class WindFieldMouseMoveHandler implements MouseMoveHandler {
+
+    private Canvas canvas;
+    private Map<ToolTip, WindDTO> windFieldPoints = null;
+    private ImageData lastImageData = null;
+    double lastToolx;
+    double lastTooly;
+   
+    
+    public WindFieldMouseMoveHandler(Canvas canvas) {
+        super();
+        this.canvas = canvas;
+    }
+
+    public void setWindFieldPoints(Map<ToolTip, WindDTO> windFieldPoints) {
+        this.windFieldPoints = windFieldPoints;
+    }
+
+    @Override
+    public void onMouseMove(MouseMoveEvent event) {
+
+        if (windFieldPoints == null) {
+            return;
+        }
+
+        double x = event.getX();
+        double y = event.getY();
+        ToolTip point = new ToolTip(x, y);
+        Context2d context2d = canvas.getContext2d();
+        if (lastImageData != null) {
+            context2d.putImageData(lastImageData, lastToolx, lastTooly);
+        }
+        lastToolx = x;
+        lastTooly = y;
+
+        lastImageData = context2d.getImageData(x, y, ToolTip.toolRectW, ToolTip.toolRectH);
+
+        if (windFieldPoints.containsKey(point)) {
+
+            WindDTO windDTO = windFieldPoints.get(point);
+            context2d.setFillStyle("#4f4f4f");
+            context2d.fillRect(x, y, ToolTip.toolRectW, ToolTip.toolRectH);
+
+            context2d.setFillStyle("#FFFFFF");
+            context2d.fillRect(x + 3, y + 3, ToolTip.toolRectW - 6, ToolTip.toolRectH - 6);
+            context2d.setFillStyle("Blue");
+            context2d.fillText("Wind " + windDTO.trueWindBearingDeg, x + 15, y + 20);
+        }
+
+    }
+
+}