diff --git a/.circleci/config.yml b/.circleci/config.yml
index a3cd7bfe..c5579475 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -16,7 +16,7 @@ jobs:
 
       # CircleCI maintains a library of pre-built images
             # documented at https://circleci.com/docs/2.0/circleci-images/
-      - image: circleci/android:api-26-alpha
+      - image: circleci/android:api-28-alpha
 
     working_directory: ~/repo
 
diff --git a/androidplot-core/src/main/java/com/androidplot/pie/PieRenderer.java b/androidplot-core/src/main/java/com/androidplot/pie/PieRenderer.java
index dc83e620..caaddc06 100644
--- a/androidplot-core/src/main/java/com/androidplot/pie/PieRenderer.java
+++ b/androidplot-core/src/main/java/com/androidplot/pie/PieRenderer.java
@@ -170,7 +170,7 @@ protected void drawSegment(Canvas canvas, RectF bounds, Segment seg, SegmentForm
             canvas.drawLine(r1Inner.x, r1Inner.y, r1Outer.x, r1Outer.y, f.getRadialEdgePaint());
             canvas.drawLine(r2Inner.x, r2Inner.y, r2Outer.x, r2Outer.y, f.getRadialEdgePaint());
         } else {
-            canvas.save(Canvas.CLIP_SAVE_FLAG);
+            canvas.save();
             Path chart = new Path();
             chart.addCircle(cx, cy, outerRad, Path.Direction.CW);
             Path inside = new Path();
diff --git a/androidplot-core/src/main/java/com/androidplot/ui/LayoutManager.java b/androidplot-core/src/main/java/com/androidplot/ui/LayoutManager.java
index e4c5cce5..0fb1a04c 100644
--- a/androidplot-core/src/main/java/com/androidplot/ui/LayoutManager.java
+++ b/androidplot-core/src/main/java/com/androidplot/ui/LayoutManager.java
@@ -92,7 +92,7 @@ public void draw(Canvas canvas) throws PlotRenderException {
         }
         for (Widget widget : elements()) {
             try {
-                canvas.save(Canvas.ALL_SAVE_FLAG);
+                canvas.save();
                 PositionMetrics metrics = widget.getPositionMetrics();
                 float elementWidth = widget.getWidthPix(displayDims.paddedRect.width());
                 float elementHeight = widget.getHeightPix(displayDims.paddedRect.height());
@@ -140,7 +140,7 @@ public void draw(Canvas canvas) throws PlotRenderException {
 
     private static void drawSpacing(Canvas canvas, RectF outer, RectF inner, Paint paint) {
         try {
-            canvas.save(Canvas.ALL_SAVE_FLAG);
+            canvas.save();
             canvas.clipRect(inner, Region.Op.DIFFERENCE);
             canvas.drawRect(outer, paint);
         } finally {
diff --git a/androidplot-core/src/main/java/com/androidplot/ui/SeriesRenderer.java b/androidplot-core/src/main/java/com/androidplot/ui/SeriesRenderer.java
index 882bdcfc..afc1b142 100644
--- a/androidplot-core/src/main/java/com/androidplot/ui/SeriesRenderer.java
+++ b/androidplot-core/src/main/java/com/androidplot/ui/SeriesRenderer.java
@@ -81,7 +81,7 @@ protected abstract void onRender(Canvas canvas, RectF plotArea, SeriesType serie
 
     public void drawSeriesLegendIcon(Canvas canvas, RectF rect, SeriesFormatterType formatter) {
         try {
-            canvas.save(Canvas.ALL_SAVE_FLAG);
+            canvas.save();
             canvas.clipRect(rect, Region.Op.INTERSECT);
             doDrawLegendIcon(canvas, rect, formatter);
         } finally {
diff --git a/androidplot-core/src/main/java/com/androidplot/ui/widget/TextLabelWidget.java b/androidplot-core/src/main/java/com/androidplot/ui/widget/TextLabelWidget.java
index 8c6e84cd..06bf54ff 100644
--- a/androidplot-core/src/main/java/com/androidplot/ui/widget/TextLabelWidget.java
+++ b/androidplot-core/src/main/java/com/androidplot/ui/widget/TextLabelWidget.java
@@ -101,7 +101,7 @@ public void doOnDraw(Canvas canvas, RectF widgetRect) {
                 Anchor.CENTER);
 
         try {
-            canvas.save(Canvas.ALL_SAVE_FLAG);
+            canvas.save();
             canvas.translate(start.x, start.y);
             switch (orientation) {
                 case HORIZONTAL:
diff --git a/androidplot-core/src/main/java/com/androidplot/xy/LineAndPointRenderer.java b/androidplot-core/src/main/java/com/androidplot/xy/LineAndPointRenderer.java
index e8c0c23b..53e80dca 100644
--- a/androidplot-core/src/main/java/com/androidplot/xy/LineAndPointRenderer.java
+++ b/androidplot-core/src/main/java/com/androidplot/xy/LineAndPointRenderer.java
@@ -309,7 +309,7 @@ protected void renderPath(Canvas canvas, RectF plotArea, Path path, PointF first
                 RectF thisRegionRectF = thisRegionTransformed.asRectF();
                 if (thisRegionRectF != null) {
                     try {
-                        canvas.save(Canvas.ALL_SAVE_FLAG);
+                        canvas.save();
                         canvas.clipPath(path);
                         canvas.drawRect(thisRegionRectF, regionFormatter.getPaint());
                     } finally {
diff --git a/androidplot-core/src/main/java/com/androidplot/xy/PanZoom.java b/androidplot-core/src/main/java/com/androidplot/xy/PanZoom.java
index a8793264..33d61369 100644
--- a/androidplot-core/src/main/java/com/androidplot/xy/PanZoom.java
+++ b/androidplot-core/src/main/java/com/androidplot/xy/PanZoom.java
@@ -2,11 +2,13 @@
 
 import android.graphics.RectF;
 import android.graphics.PointF;
+import android.support.annotation.NonNull;
 import android.view.*;
 
 import com.androidplot.*;
 import com.androidplot.util.*;
 
+import java.io.Serializable;
 import java.util.*;
 
 /**
@@ -35,6 +37,7 @@ public class PanZoom implements View.OnTouchListener {
     // rectangle created by the space between two fingers
     protected RectF fingersRect;
     private View.OnTouchListener delegate;
+    private State state = new State();
 
     // Definition of the touch states
     protected enum DragState {
@@ -95,7 +98,42 @@ public enum ZoomLimit {
         MIN_TICKS
     }
 
-    protected PanZoom(XYPlot plot, Pan pan, Zoom zoom) {
+    // TODO: consider making this immutable / threadsafe
+    public static class State implements Serializable {
+        private Number domainLowerBoundary;
+        private Number domainUpperBoundary;
+        private Number rangeLowerBoundary;
+        private Number rangeUpperBoundary;
+        private BoundaryMode domainBoundaryMode;
+        private BoundaryMode rangeBoundaryMode;
+
+        public void setDomainBoundaries(Number lowerBoundary, Number upperBoundary, BoundaryMode mode) {
+            this.domainLowerBoundary = lowerBoundary;
+            this.domainUpperBoundary = upperBoundary;
+            this.domainBoundaryMode = mode;
+        }
+
+        public void setRangeBoundaries(Number lowerBoundary, Number upperBoundary, BoundaryMode mode) {
+            this.rangeLowerBoundary = lowerBoundary;
+            this.rangeUpperBoundary = upperBoundary;
+            this.rangeBoundaryMode = mode;
+        }
+
+        public void applyDomainBoundaries(@NonNull XYPlot plot) {
+            plot.setDomainBoundaries(domainLowerBoundary, domainUpperBoundary, domainBoundaryMode);
+        }
+
+        public void applyRangeBoundaries(@NonNull XYPlot plot) {
+            plot.setRangeBoundaries(rangeLowerBoundary, rangeUpperBoundary, rangeBoundaryMode);
+        }
+
+        public void apply(@NonNull XYPlot plot) {
+            applyDomainBoundaries(plot);
+            applyRangeBoundaries(plot);
+        }
+    }
+
+    protected PanZoom(@NonNull XYPlot plot, Pan pan, Zoom zoom) {
         this.plot = plot;
         this.pan = pan;
         this.zoom = zoom;
@@ -103,13 +141,32 @@ protected PanZoom(XYPlot plot, Pan pan, Zoom zoom) {
     }
 
     // additional constructor not to break api
-    protected PanZoom(XYPlot plot, Pan pan, Zoom zoom, ZoomLimit limit) {
+    protected PanZoom(@NonNull XYPlot plot, Pan pan, Zoom zoom, ZoomLimit limit) {
         this.plot = plot;
         this.pan = pan;
         this.zoom = zoom;
         this.zoomLimit = limit;
     }
 
+    public State getState() {
+        return this.state;
+    }
+
+    public void setState(@NonNull State state) {
+        this.state = state;
+        state.apply(plot);
+    }
+
+    protected void adjustRangeBoundary(Number lower, Number upper,  BoundaryMode mode) {
+        state.setRangeBoundaries(lower, upper, mode);
+        state.applyRangeBoundaries(plot);
+    }
+
+    protected void adjustDomainBoundary(Number lower, Number upper, BoundaryMode mode) {
+        state.setDomainBoundaries(lower, upper, mode);
+        state.applyDomainBoundaries(plot);
+    }
+
     /**
      * Convenience method for enabling pan/zoom behavior on an instance of {@link XYPlot}, using
      * a default behavior of {@link Pan#BOTH} and {@link Zoom#SCALE}.
@@ -117,7 +174,7 @@ protected PanZoom(XYPlot plot, Pan pan, Zoom zoom, ZoomLimit limit) {
      * @param plot
      * @return
      */
-    public static PanZoom attach(XYPlot plot) {
+    public static PanZoom attach(@NonNull XYPlot plot) {
         return attach(plot, Pan.BOTH, Zoom.SCALE);
     }
 
@@ -130,7 +187,7 @@ public static PanZoom attach(XYPlot plot) {
      * @param zoom
      * @return
      */
-    public static PanZoom attach(XYPlot plot, Pan pan, Zoom zoom) {
+    public static PanZoom attach(@NonNull XYPlot plot, @NonNull Pan pan, @NonNull Zoom zoom) {
         return attach(plot,pan,zoom, ZoomLimit.OUTER);
     }
 
@@ -142,7 +199,7 @@ public static PanZoom attach(XYPlot plot, Pan pan, Zoom zoom) {
      * @param limit
      * @return
      */
-    public static PanZoom attach(XYPlot plot, Pan pan, Zoom zoom, ZoomLimit limit) {
+    public static PanZoom attach(@NonNull XYPlot plot, @NonNull Pan pan, @NonNull Zoom zoom, @NonNull ZoomLimit limit) {
         PanZoom pz = new PanZoom(plot, pan, zoom, limit);
         plot.setOnTouchListener(pz);
         return pz;
@@ -237,12 +294,12 @@ protected void pan(final MotionEvent motionEvent) {
         if (EnumSet.of(Pan.HORIZONTAL, Pan.BOTH).contains(pan)) {
             Region newBounds = new Region();
             calculatePan(oldFirstFinger, newBounds, true);
-            plot.setDomainBoundaries(newBounds.getMin(), newBounds.getMax(), BoundaryMode.FIXED);
+            adjustDomainBoundary(newBounds.getMin(), newBounds.getMax(), BoundaryMode.FIXED);
         }
         if (EnumSet.of(Pan.VERTICAL, Pan.BOTH).contains(pan)) {
             Region newBounds = new Region();
             calculatePan(oldFirstFinger, newBounds, false);
-            plot.setRangeBoundaries(newBounds.getMin(), newBounds.getMax(), BoundaryMode.FIXED);
+            adjustRangeBoundary(newBounds.getMin(), newBounds.getMax(), BoundaryMode.FIXED);
         }
 
         plot.redraw();
@@ -291,10 +348,9 @@ protected void calculatePan(final PointF oldFirstFinger, Region bounds, final bo
     }
 
     protected boolean isValidScale(float scale) {
-        if (Float.isInfinite(scale) || Float.isNaN(scale) || scale > -0.001 && scale < 0.001) {
-            return false;
-        }
-        return true;
+        return !Float.isInfinite(scale)
+                && !Float.isNaN(scale)
+                && (!(scale > -0.001) || !(scale < 0.001));
     }
 
     protected void zoom(final MotionEvent motionEvent) {
@@ -349,14 +405,14 @@ protected void zoom(final MotionEvent motionEvent) {
                 Zoom.STRETCH_BOTH,
                 Zoom.SCALE).contains(zoom)) {
             calculateZoom(newRect, scaleX, true);
-            plot.setDomainBoundaries(newRect.left, newRect.right, BoundaryMode.FIXED);
+            adjustDomainBoundary(newRect.left, newRect.right, BoundaryMode.FIXED);
         }
         if (EnumSet.of(
                 Zoom.STRETCH_VERTICAL,
                 Zoom.STRETCH_BOTH,
                 Zoom.SCALE).contains(zoom)) {
             calculateZoom(newRect, scaleY, false);
-            plot.setRangeBoundaries(newRect.top, newRect.bottom, BoundaryMode.FIXED);
+            adjustRangeBoundary(newRect.top, newRect.bottom, BoundaryMode.FIXED);
         }
         plot.redraw();
     }
diff --git a/androidplot-core/src/main/java/com/androidplot/xy/XYGraphWidget.java b/androidplot-core/src/main/java/com/androidplot/xy/XYGraphWidget.java
index 1ca3de77..22c551e9 100644
--- a/androidplot-core/src/main/java/com/androidplot/xy/XYGraphWidget.java
+++ b/androidplot-core/src/main/java/com/androidplot/xy/XYGraphWidget.java
@@ -847,7 +847,7 @@ protected void drawData(Canvas canvas) throws PlotRenderException {
         }
         try {
             if (isGridClippingEnabled) {
-                canvas.save(Canvas.ALL_SAVE_FLAG);
+                canvas.save();
                 canvas.clipRect(gridRect, android.graphics.Region.Op.INTERSECT);
             }
 
diff --git a/build.gradle b/build.gradle
index a7aa9c13..d45fb28b 100644
--- a/build.gradle
+++ b/build.gradle
@@ -23,10 +23,10 @@ allprojects {
 }
 
 ext {
-    theCompileSdkVersion = 26
-    theTargetSdkVersion = 26
+    theCompileSdkVersion = 28
+    theTargetSdkVersion = 28
     theMinSdkVersion = 5
-    theVersionName = '1.5.5'
+    theVersionName = '1.5.6'
     theVersionCode = 0
 }
 
diff --git a/demoapp/src/main/java/com/androidplot/demos/SimpleXYPlotActivity.java b/demoapp/src/main/java/com/androidplot/demos/SimpleXYPlotActivity.java
index 6238e4df..46118949 100644
--- a/demoapp/src/main/java/com/androidplot/demos/SimpleXYPlotActivity.java
+++ b/demoapp/src/main/java/com/androidplot/demos/SimpleXYPlotActivity.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2015 AndroidPlot.com
+ * Copyright 2018 AndroidPlot.com
  *
  *    Licensed under the Apache License, Version 2.0 (the "License");
  *    you may not use this file except in compliance with the License.
@@ -21,7 +21,6 @@
 import android.os.Bundle;
 import android.support.annotation.NonNull;
 
-import com.androidplot.ui.Insets;
 import com.androidplot.util.PixelUtils;
 import com.androidplot.xy.CatmullRomInterpolator;
 import com.androidplot.xy.LineAndPointFormatter;
@@ -49,7 +48,7 @@ public void onCreate(Bundle savedInstanceState)
         setContentView(R.layout.simple_xy_plot_example);
 
         // initialize our XYPlot reference:
-        plot = (XYPlot) findViewById(R.id.plot);
+        plot = findViewById(R.id.plot);
 
         // create a couple arrays of y-values to plot:
         final Number[] domainLabels = {1, 2, 3, 6, 7, 8, 9, 10, 13, 14};
@@ -101,19 +100,5 @@ public Object parseObject(String source, @NonNull ParsePosition pos) {
                 return null;
             }
         });
-
-        new Thread(new Runnable() {
-
-            @Override
-            public void run() {
-                try {
-                    Thread.sleep(2000);
-                } catch (InterruptedException e) {
-                    throw new RuntimeException(e);
-                }
-                plot.getGraph().setGridInsets(new Insets(120, 120, 120, 120));
-                plot.redraw();
-            }
-        }).start();
     }
 }
diff --git a/demoapp/src/main/java/com/androidplot/demos/TouchZoomExampleActivity.java b/demoapp/src/main/java/com/androidplot/demos/TouchZoomExampleActivity.java
index c4105cde..dfae19d9 100644
--- a/demoapp/src/main/java/com/androidplot/demos/TouchZoomExampleActivity.java
+++ b/demoapp/src/main/java/com/androidplot/demos/TouchZoomExampleActivity.java
@@ -152,6 +152,7 @@ public void onNothingSelected(AdapterView<?> parent) {
             }
         });
 
+
         zoomSpinner.setAdapter(
                 new ArrayAdapter<>(this, R.layout.spinner_item, PanZoom.Zoom.values()));
         zoomSpinner.setSelection(panZoom.getZoom().ordinal());
@@ -167,5 +168,19 @@ public void onNothingSelected(AdapterView<?> parent) {
             }
         });
     }
+
+    // (optional) save the current pan/zoom state
+    @Override
+    public void onSaveInstanceState(Bundle bundle) {
+         bundle.putSerializable("pan-zoom-state", panZoom.getState());
+    }
+
+    // (optional) restore the previously saved pan/zoom state
+    @Override
+    public void onRestoreInstanceState(Bundle bundle) {
+        PanZoom.State state = (PanZoom.State) bundle.getSerializable("pan-zoom-state");
+        panZoom.setState(state);
+        plot.redraw();
+    }
 }
 
diff --git a/docs/quickstart.md b/docs/quickstart.md
index e6ae7ff5..ffc3827d 100644
--- a/docs/quickstart.md
+++ b/docs/quickstart.md
@@ -14,7 +14,7 @@ To use the library in your gradle project add the following to your build.gradle
 
 ```groovy
 dependencies {
-    compile "com.androidplot:androidplot-core:1.5.5"
+    compile "com.androidplot:androidplot-core:1.5.6"
 }
 ```
 
diff --git a/docs/release_notes.md b/docs/release_notes.md
index 762ac5a6..6bebeb8c 100644
--- a/docs/release_notes.md
+++ b/docs/release_notes.md
@@ -2,6 +2,11 @@
 For details on what to expect in general when updating to a new version of Androiplot, check out the
 [versioning doc](versioning.md).
 
+# 1.5.6
+
+* Adds convenience methods for saving / restoring `PanZoom` state.
+* (#80) Targets SDK 28, fixing compatibility issues.
+
 # 1.5.5
 
 * (#76) Fixed a bug that could cause a deadlock when grid steps are much larger than actual plot range.
diff --git a/docs/xyplot.md b/docs/xyplot.md
index 2dab08db..99128178 100644
--- a/docs/xyplot.md
+++ b/docs/xyplot.md
@@ -217,6 +217,25 @@ then the plot will pan and zoom on both axes infinitely.  To set the plot's oute
 plot.getOuterLimits().set(0, 100, 0, 100);
 ```
 
+# Saving & Restoring PanZoom State
+The `PanZoom` class provides convenience methods for saving and restoring state from your `Activity`:
+
+```java
+// save the current pan/zoom state
+@Override
+public void onSaveInstanceState(Bundle bundle) {
+     bundle.putSerializable("pan-zoom-state", panZoom.getState());
+}
+
+// restore the previously saved pan/zoom state
+@Override
+public void onRestoreInstanceState(Bundle bundle) {
+    PanZoom.State state = (PanZoom.State) bundle.getSerializable("pan-zoom-state");
+    panZoom.setState(state);
+    plot.redraw();
+}
+```
+
 For a more detailed look at pan & zoom behavior, check out the [Touch Zoom Example source code](../demoapp/src/main/java/com/androidplot/demos/TouchZoomExampleActivity.java).
 
 # Series Renderers