IrPlotter: improved mouse-based zooming. Resolves #361.

Minor tweaks in IrPlotter.

Author: bengtmartensson

src/main/java/org/harctoolbox/guicomponents/IrPlotter.java

@@ -21,6 +21,7 @@
 import java.awt.Dimension;
 import java.awt.Graphics;
 import java.awt.event.MouseEvent;
+import java.awt.event.MouseWheelEvent;
 import java.io.IOException;
 import javax.swing.JMenu;
 import javax.swing.JMenuItem;
@@ -68,6 +69,10 @@ public class IrPlotter extends HarcPanel {
     private final static Color endingColor = Color.GREEN;
     private final static int invalid = -1;
 
+    private final static int RESET_MOUSE_BUTTON = 6;
+    private final static double BASIS = 1.05;
+    private final static double LOGBASIS = Math.log(BASIS);
+
     /** max horizontal coordinate, in microseconds */
     private int xmin = 0;
     private int xmax = 200000;
@@ -193,7 +198,8 @@ private void setDragBegin(int x) {
 
     private void setDragEnd(int x) {
         if (dragBeginX != invalid && Math.abs(dragBeginX - x) > dragThreshold) {
-            xmin = screenX2x(Math.min(dragBeginX, x));
+            // Nothing interesting is going on for negative x's, so force xmin non-negative
+            xmin = Math.max(screenX2x(Math.min(dragBeginX, x)), 0);
             xmax = screenX2x(Math.max(dragBeginX, x));
             //System.err.println("End: " + x + " " + screenX2x(x));
         }
@@ -329,7 +335,7 @@ private int[] getTickValues(int xmin, int xmax, int pixelWidth) {
         int tickWidth = rounder((int)Math.round(goalWidth));
         useMilliSeconds = tickWidth >= 5000;
         int newXmin = xmin/tickWidth*tickWidth;
-        this.xmin = newXmin;
+        //this.xmin = newXmin;
         int noTicks = (int) Math.ceil(((double)(xmax-newXmin))/tickWidth) + 1;
         if (noTicks <= 0) {
             System.err.println(">>>>>>>>>>>>>>" + xmax + " " + newXmin + " " + tickWidth + " " + goalWidth);
@@ -398,14 +404,38 @@ else if (evt.getButton() == MouseEvent.BUTTON3)
 
             @Override
             public void mouseReleased(java.awt.event.MouseEvent evt) {
-                if (evt.getButton() == MouseEvent.BUTTON1)
-                    setDragEnd(evt.getX());
-                else if (evt.getButton() == MouseEvent.BUTTON3)
-                    if (evt.isPopupTrigger())
-                        plotterPopupMenu.show(evt.getComponent(), evt.getX(), evt.getY());
+                switch (evt.getButton()) {
+                    case MouseEvent.BUTTON1:
+                        setDragEnd(evt.getX());
+                        break;
+                    case MouseEvent.BUTTON3:
+                        if (evt.isPopupTrigger())
+                            plotterPopupMenu.show(evt.getComponent(), evt.getX(), evt.getY());
+                        break;
+                    case RESET_MOUSE_BUTTON:
+                        reset();
+                        break;
+                    default:
+                            ; // nothing
+                }
             }
         });
 
+        addMouseWheelListener((MouseWheelEvent evt) -> {
+            int screenX = evt.getX();
+            int myX = screenX2x(screenX);
+            double length = xmax - xmin;
+            double frac = (myX - xmin) / length;
+            double noClicks = evt.getPreciseWheelRotation();
+            double factor = Math.exp(noClicks * LOGBASIS);
+            double toReduce = (factor - 1.0) * length;
+            double left = toReduce * frac;
+            double right = toReduce * (1.0 - frac);
+            xmin += (int) left;
+            xmax -= (int) right;
+            repaint();
+        });
+
         addMouseMotionListener(new java.awt.event.MouseMotionAdapter() {
             @Override
             public void mouseDragged(java.awt.event.MouseEvent evt) {

src/main/java/org/harctoolbox/irscrutinizer/GuiMain.form

@@ -2904,7 +2904,7 @@
                             <BevelBorder bevelType="1"/>
                           </Border>
                         </Property>
-                        <Property name="toolTipText" type="java.lang.String" value="Plot of captured IR signal. Press right mouse button for a menu."/>
+                        <Property name="toolTipText" type="java.lang.String" value="Plot of IR signal above. Press right mouse button for a menu, mouse wheel to zoom, left mouse buttol + drag to zoom selection."/>
                         <Property name="autoscrolls" type="boolean" value="true"/>
                         <Property name="preferredSize" type="java.awt.Dimension" editor="org.netbeans.beaninfo.editors.DimensionEditor">
                           <Dimension value="[749, 100]"/>

src/main/java/org/harctoolbox/irscrutinizer/GuiMain.java

@@ -3716,7 +3716,7 @@ public void actionPerformed(java.awt.event.ActionEvent evt) {
         plotScrollPane.setVerticalScrollBarPolicy(javax.swing.ScrollPaneConstants.VERTICAL_SCROLLBAR_NEVER);
 
         irPlotter.setBorder(new javax.swing.border.SoftBevelBorder(javax.swing.border.BevelBorder.LOWERED));
-        irPlotter.setToolTipText("Plot of captured IR signal. Press right mouse button for a menu.");
+        irPlotter.setToolTipText("Plot of IR signal above. Press right mouse button for a menu, mouse wheel to zoom, left mouse buttol + drag to zoom selection.");
         irPlotter.setAutoscrolls(true);
         irPlotter.setPreferredSize(new java.awt.Dimension(749, 100));