Can someone help me edit the code provided by the guys who made androidplot for the touch-zoom example? I plan to use it but I noticed that everytime I zoom in on the plot I can't zoom out back to it's original size.
Here is the code for that https://bitbucket.org/androidplot/androidplot/src/397fac6a3541b4020a716e958a9c0b42bd2450fd/Examples/DemoApp/src/com/androidplot/demos/TouchZoomExampleActivity.java?at=master
I repaired the androidplot touchzoom example, it now scrolls and zooms as it should without losing the size of the boundary this is the code for mainActivity.java
package com.tutorialz.paul.scaleplotdesign;
import java.util.ArrayList;
import java.util.Random;
import android.app.Activity;
import android.graphics.PointF;
import android.os.Bundle;
import android.util.FloatMath;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.Button;
import android.widget.Toast;
import com.androidplot.Plot;
import com.androidplot.ui.SizeLayoutType;
import com.androidplot.ui.SizeMetrics;
import com.androidplot.xy.BoundaryMode;
import com.androidplot.xy.LineAndPointFormatter;
import com.androidplot.xy.PointLabelFormatter;
import com.androidplot.xy.SimpleXYSeries;
import com.androidplot.xy.XYPlot;
public class MainActivity extends Activity implements OnTouchListener {
private static final int SERIES_SIZE = 200;
private XYPlot plotOne, plotTwo;
private SimpleXYSeries series1 = null;
private SimpleXYSeries series2 = null;
private PointF minXY;
private PointF maxXY;
float zoomRatio = 2, leftBoundary, rightBoundary;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//plot setup
plotOne = (XYPlot) findViewById(R.id.myFirstXYPlot);
plotOne.setOnTouchListener(this);
plotOne.getGraphWidget().setTicksPerRangeLabel(2);
plotOne.getGraphWidget().setTicksPerDomainLabel(2);
plotOne.getGraphWidget().setRangeLabelWidth(25);
plotOne.setRangeLabel("");
plotOne.setDomainLabel("");
plotOne.setBorderStyle(Plot.BorderStyle.NONE, null, null);
plotOne.getLayoutManager().remove(plotOne.getLegendWidget());
plotOne.getGraphWidget().setSize(new SizeMetrics(0,SizeLayoutType.FILL,
0, SizeLayoutType.FILL));
plotOne.setPlotMargins(0,0,0,0);
plotTwo = (XYPlot) findViewById(R.id.mySecondXYPlot);
plotTwo.setOnTouchListener(this);
plotTwo.getGraphWidget().setTicksPerRangeLabel(2);
plotTwo.getGraphWidget().setTicksPerDomainLabel(2);
plotTwo.getGraphWidget().setRangeLabelWidth(25);
plotTwo.setRangeLabel("");
plotTwo.setDomainLabel("");
plotTwo.setBorderStyle(Plot.BorderStyle.NONE, null, null);
plotTwo.getLayoutManager().remove(plotTwo.getLegendWidget());
plotTwo.getGraphWidget().setSize(new SizeMetrics(0,SizeLayoutType.FILL,
0, SizeLayoutType.FILL));
plotTwo.setPlotMargins(0,0,0,0);
//********
//series setup
series1 = new SimpleXYSeries("PARAM");
populateSeries(series1, 25);
//series1.setModel(values1, SimpleXYSeries.ArrayFormat.Y_VALS_ONLY);
series1.useImplicitXVals();
LineAndPointFormatter line1 = new LineAndPointFormatter();
line1.setPointLabelFormatter(new PointLabelFormatter());
line1.configure(getApplicationContext(), R.xml.f1);
series2 = new SimpleXYSeries("PARAM");
populateSeries(series2, 15);
//series2.setModel(values1, SimpleXYSeries.ArrayFormat.Y_VALS_ONLY);
series2.useImplicitXVals();
LineAndPointFormatter line2 = new LineAndPointFormatter();
line2.setPointLabelFormatter(new PointLabelFormatter());
line2.configure(getApplicationContext(), R.xml.f2);
plotOne.addSeries(series1, line1);
plotTwo.addSeries(series2, line2);
plotOne.redraw();
plotTwo.redraw();
plotOne.calculateMinMaxVals();
minXY = new PointF(plotOne.getCalculatedMinX().floatValue(),
plotOne.getCalculatedMinY().floatValue());
maxXY = new PointF(plotOne.getCalculatedMaxX().floatValue(),
plotOne.getCalculatedMaxY().floatValue());
leftBoundary = series1.getX(0).floatValue();
rightBoundary = series1.getX(series1.size() - 1).floatValue();
}
private void populateSeries(SimpleXYSeries series, int max) {
Random r = new Random();
for(int i = 0; i < SERIES_SIZE; i++) {
series.addLast(i, r.nextInt(max));
}
}
//*****************
// Definition of the touch states
static final int NONE = 0;
static final int ONE_FINGER_DRAG = 1;
static final int TWO_FINGERS_DRAG = 2;
int mode = NONE;
PointF firstFinger;
float distBetweenFingers;
boolean stopThread = false;
@Override
public boolean onTouch(View arg0, MotionEvent event) {
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN: // Start gesture
firstFinger = new PointF(event.getX(), event.getY());
mode = ONE_FINGER_DRAG;
stopThread = true;
break;
case MotionEvent.ACTION_POINTER_UP:
case MotionEvent.ACTION_UP:
mode = NONE;
break;
case MotionEvent.ACTION_POINTER_DOWN: // second finger
distBetweenFingers = spacing(event);
// the distance check is done to avoid false alarms
if (distBetweenFingers > 5f) {
mode = TWO_FINGERS_DRAG;
}
break;
case MotionEvent.ACTION_MOVE:
if (mode == ONE_FINGER_DRAG) {
PointF oldFirstFinger = firstFinger;
firstFinger = new PointF(event.getX(), event.getY());
scroll(oldFirstFinger.x - firstFinger.x);
plotOne.setDomainBoundaries(minXY.x, maxXY.x,
BoundaryMode.FIXED);
plotOne.redraw();
plotTwo.setDomainBoundaries(minXY.x, maxXY.x,
BoundaryMode.FIXED);
plotTwo.redraw();
} else if (mode == TWO_FINGERS_DRAG) {
float oldDist = distBetweenFingers;
distBetweenFingers = spacing(event);
zoom(oldDist / distBetweenFingers);
plotOne.setDomainBoundaries(minXY.x, maxXY.x,
BoundaryMode.FIXED);
plotOne.redraw();
plotTwo.setDomainBoundaries(minXY.x, maxXY.x,
BoundaryMode.FIXED);
plotTwo.redraw();
}
break;
}
return true;
}
private void zoom(float scale) {
float domainSpan = maxXY.x - minXY.x;
float oldMax = maxXY.x;
float oldMin = minXY.x;
float domainMidPoint = maxXY.x - (domainSpan / 2.0f);
float offset = domainSpan * scale / 2.0f;
minXY.x = domainMidPoint - offset;
maxXY.x = domainMidPoint + offset;
float newSpan = maxXY.x - minXY.x;
if (newSpan < (float)5) {
minXY.x = oldMin;
maxXY.x = oldMax;
}
if (minXY.x < leftBoundary) {
minXY.x = leftBoundary;
maxXY.x = leftBoundary + domainSpan * zoomRatio;
if (maxXY.x > series1.getX(series1.size() - 1).floatValue())
maxXY.x = rightBoundary;
}
if (maxXY.x > series1.getX(series1.size() - 1).floatValue()) {
maxXY.x = rightBoundary;
minXY.x = rightBoundary - domainSpan * zoomRatio;
if (minXY.x < leftBoundary) minXY.x = leftBoundary;
}
}
private void scroll(float pan) {
float domainSpan = maxXY.x - minXY.x;
float step = domainSpan / plotOne.getWidth();
float offset = pan * step;
minXY.x = minXY.x + offset;
maxXY.x = maxXY.x + offset;
if (minXY.x < leftBoundary) {
minXY.x = leftBoundary;
maxXY.x = leftBoundary + domainSpan;
}
if (maxXY.x > series1.getX(series1.size() - 1).floatValue()) {
maxXY.x = rightBoundary;
minXY.x = rightBoundary - domainSpan;
}
}
private float spacing(MotionEvent event) {
float x = event.getX(0) - event.getX(1);
float y = event.getY(0) - event.getY(1);
return FloatMath.sqrt(x * x + y * y);
}
}
and this is for main_activity.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="300dp"
android:orientation="vertical"
android:background="#FF727272"
android:layout_margin="10dp">
<com.androidplot.xy.XYPlot
android:id="@+id/myFirstXYPlot"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
androidPlot.graphWidget.paddingLeft="20dp"
androidPlot.graphWidget.paddingRight="20dp"
androidPlot.graphWidget.backgroundPaint.color="#ff727272"
androidPlot.graphWidget.gridBackgroundPaint.color="#ffe3e3e3"
androidPlot.graphWidget.rangeLabelPaint.textSize="10dp"
androidPlot.graphWidget.domainLabelPaint.textSize="10dp"
androidplot.renderMode="use_background_thread"
/>
<com.androidplot.xy.XYPlot
android:id="@+id/mySecondXYPlot"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_weight="1"
androidPlot.graphWidget.backgroundPaint.color="#ff727272"
androidPlot.graphWidget.gridBackgroundPaint.color="#ffe3e3e3"
androidPlot.graphWidget.paddingLeft="20dp"
androidPlot.graphWidget.paddingRight="20dp"
androidPlot.graphWidget.rangeLabelPaint.textSize="10dp"
androidPlot.graphWidget.domainLabelPaint.textSize="10dp"
androidplot.renderMode="use_background_thread"
/>
</LinearLayout>
</LinearLayout>