From aee8ef44bb9b36883eafd2381148b7e6ade0211b Mon Sep 17 00:00:00 2001
From: OliE <olie.xdev@googlemail.com>
Date: Sat, 4 Mar 2017 14:51:13 +0100
Subject: [PATCH] reset the viewport of the diagram on long press

---
 .../health/openscale/gui/GraphFragment.java   | 23 ++++++++++++++++---
 1 file changed, 20 insertions(+), 3 deletions(-)

diff --git a/android_app/app/src/main/java/com/health/openscale/gui/GraphFragment.java b/android_app/app/src/main/java/com/health/openscale/gui/GraphFragment.java
index e9261e53..b4b24d6d 100644
--- a/android_app/app/src/main/java/com/health/openscale/gui/GraphFragment.java
+++ b/android_app/app/src/main/java/com/health/openscale/gui/GraphFragment.java
@@ -24,7 +24,9 @@ import android.graphics.Color;
 import android.os.Bundle;
 import android.preference.PreferenceManager;
 import android.support.v4.app.Fragment;
+import android.view.GestureDetector;
 import android.view.LayoutInflater;
+import android.view.MotionEvent;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.TextView;
@@ -60,6 +62,7 @@ public class GraphFragment extends Fragment implements FragmentUpdateListener {
 	private View graphView;
 	private LineChartView chartTop;
     private ColumnChartView chartBottom;
+    private Viewport resetViewport;
     private TextView txtYear;
     private SharedPreferences prefs;
 
@@ -83,6 +86,7 @@ public class GraphFragment extends Fragment implements FragmentUpdateListener {
 		chartTop = (LineChartView) graphView.findViewById(R.id.chart_top);
         chartBottom = (ColumnChartView) graphView.findViewById(R.id.chart_bottom);
 
+        chartTop.setOnTouchListener(new ChartTopListener());
         chartTop.setOnValueTouchListener(new ChartTopValueTouchListener());
         chartBottom.setOnValueTouchListener(new ChartBottomValueTouchListener());
 
@@ -236,10 +240,10 @@ public class GraphFragment extends Fragment implements FragmentUpdateListener {
 
         chartTop.setLineChartData(lineData);
 
-        Viewport v = new Viewport(0, chartTop.getCurrentViewport().top+4, maxDays-1, chartTop.getCurrentViewport().bottom-4);
+        resetViewport = new Viewport(0, chartTop.getCurrentViewport().top+4, maxDays-1, chartTop.getCurrentViewport().bottom-4);
 
-        chartTop.setMaximumViewport(v);
-        chartTop.setCurrentViewport(v);
+        chartTop.setMaximumViewport(resetViewport);
+        chartTop.setCurrentViewport(resetViewport);
     }
 
     private void generateColumnData()
@@ -297,6 +301,19 @@ public class GraphFragment extends Fragment implements FragmentUpdateListener {
         }
     }
 
+    private class ChartTopListener implements View.OnTouchListener {
+        final GestureDetector gestureDetector = new GestureDetector(new GestureDetector.SimpleOnGestureListener() {
+            public void onLongPress(MotionEvent e) {
+                chartTop.setCurrentViewport(resetViewport);
+            }
+        });
+
+        @Override
+        public boolean onTouch (View v, MotionEvent event) {
+            return gestureDetector.onTouchEvent(event);
+        }
+    }
+
     private class ChartTopValueTouchListener implements LineChartOnValueSelectListener {
         @Override
         public void onValueSelected(int lineIndex, int pointIndex, PointValue pointValue) {