diff --git a/CHANGELOG.md b/CHANGELOG.md
index 73cbf7e4..8e96d0d1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,9 @@
+# Next
+
+- Library: Fix Value size (ValueFactory) and property access
+- Generator: Add cairo PNG support
+- Examples: ImageIO sample
+
 # 0.6.0
 
 - Generator: Add markdown summary logs
diff --git a/examples/src/main/java/examples/App.java b/examples/src/main/java/examples/App.java
index 519fb8af..077080d3 100644
--- a/examples/src/main/java/examples/App.java
+++ b/examples/src/main/java/examples/App.java
@@ -28,6 +28,7 @@
 import examples.gtk4_tutorial.CustomDrawing;
 import examples.gtk4_tutorial.ExampleApplication;
 import examples.gtk4_tutorial.UiBuilderExample;
+import examples.image_io.ImageIo;
 
 public class App {
 
@@ -71,6 +72,7 @@ public static void main (String[] args)  {
             addSample(demoList, window, new ExampleApplication(app));
             addSample(demoList, window, new GlibSettings());
             addSample(demoList, window, new Accordion());
+            addSample(demoList, window, new ImageIo());
 
             window.present();
         });
diff --git a/examples/src/main/java/examples/ImageBridge.java b/examples/src/main/java/examples/ImageBridge.java
index c13568f8..8963fc6b 100644
--- a/examples/src/main/java/examples/ImageBridge.java
+++ b/examples/src/main/java/examples/ImageBridge.java
@@ -90,14 +90,12 @@ private Pixbuf loadPixbuf(int width, int height) throws IOException {
         }
     }
 
-    private boolean drawLogo(Context context) {
+    private void drawLogo(Context context) {
         if (pixbuf != null) {
             context.save();
             Gdk.cairoSetSourcePixbuf(context, pixbuf, 0, 0);
             context.paint();
-            return true;
         }
-        return false;
     }
 
     @Override
diff --git a/examples/src/main/java/examples/gtk4_demo/Pixbufs.java b/examples/src/main/java/examples/gtk4_demo/Pixbufs.java
index 2a751352..1070babe 100644
--- a/examples/src/main/java/examples/gtk4_demo/Pixbufs.java
+++ b/examples/src/main/java/examples/gtk4_demo/Pixbufs.java
@@ -57,7 +57,7 @@ public class Pixbufs implements DemoInterface {
     private final Pixbuf[] images = new Pixbuf[IMAGE_NAMES.length];
 
     /* Widgets */
-    private DrawingArea da;
+    private DrawingArea drawingArea;
 
     private static final long CYCLE_TIME = 3000000; /* 3 seconds */
     private long startTime;
@@ -163,7 +163,7 @@ private boolean onTick(FrameClock frameClock) {
                         overallAlpha);
             }
         }
-        da.queueDraw();
+        drawingArea.queueDraw();
         return GlibConstants.SOURCE_CONTINUE;
     }
 
@@ -175,11 +175,11 @@ public Window runDemo() {
         try  {
             loadPixbufs();
             frame = new Pixbuf(Colorspace.RGB, false, 8, backWidth, backHeight);
-            da = new DrawingArea();
+            drawingArea = new DrawingArea();
 
 
-            da.setDrawFunc((cb, drawingArea, cr, width, height, userData) -> onDraw(cr), null, (cb, data) -> {});
-            demoWindow.setChild(da);
+            drawingArea.setDrawFunc((cb, drawingArea, cr, width, height, userData) -> onDraw(cr), null, (cb, data) -> {});
+            demoWindow.setChild(drawingArea);
             demoWindow.setSizeRequest(backWidth, backHeight);
             demoWindow.addTickCallback((cb, widget, frame_clock, user_data) -> onTick(frame_clock), null, (cb, data) -> {});
 
@@ -193,7 +193,7 @@ public Window runDemo() {
                     new Str("Failed to load an image: " + e.getMessage()));
 
             dialog.onResponse(response_id -> demoWindow.destroy());
-            dialog.show();
+            dialog.present();
         }
         return demoWindow;
     }
diff --git a/examples/src/main/java/examples/image_io/ImageIo.java b/examples/src/main/java/examples/image_io/ImageIo.java
new file mode 100644
index 00000000..3b2c2743
--- /dev/null
+++ b/examples/src/main/java/examples/image_io/ImageIo.java
@@ -0,0 +1,227 @@
+package examples.image_io;
+
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+
+import ch.bailu.gtk.cairo.Cairo;
+import ch.bailu.gtk.cairo.Format;
+import ch.bailu.gtk.cairo.Surface;
+import ch.bailu.gtk.gdk.Gdk;
+import ch.bailu.gtk.gdkpixbuf.Pixbuf;
+import ch.bailu.gtk.gio.File;
+import ch.bailu.gtk.gtk.Box;
+import ch.bailu.gtk.gtk.Button;
+import ch.bailu.gtk.gtk.DrawingArea;
+import ch.bailu.gtk.gtk.DropDown;
+import ch.bailu.gtk.gtk.FileDialog;
+import ch.bailu.gtk.gtk.Label;
+import ch.bailu.gtk.gtk.Orientation;
+import ch.bailu.gtk.gtk.Widget;
+import ch.bailu.gtk.gtk.Window;
+import ch.bailu.gtk.lib.bridge.Image;
+import ch.bailu.gtk.lib.util.JavaResource;
+import ch.bailu.gtk.type.Str;
+import ch.bailu.gtk.type.Strs;
+import ch.bailu.gtk.type.exception.AllocationError;
+import examples.DemoInterface;
+
+public class ImageIo implements DemoInterface {
+    private static int SIZE = 500;
+    private static Str TITLE = new Str("Image IO");
+    private static Str DESCRIPTION = new Str("Load and save images using different methods");
+
+    private DrawingArea drawingArea;
+    private Surface imageSurface;
+    private Label statusLabel;
+    private DropDown methodDropdown;
+
+    @Override
+    public Window runDemo() {
+        statusLabel = new Label(TITLE);
+        statusLabel.setXalign(0);
+
+        var vbox = new Box(Orientation.VERTICAL, 5);
+        var hbox = new Box(Orientation.HORIZONTAL, 5);
+        var demoWindow = new Window();
+
+        hbox.append(createOpenButton(demoWindow));
+        hbox.append(createSaveButton(demoWindow));
+        hbox.append(createLoadDefaultButton());
+        hbox.append(new Label("Method:"));
+        hbox.append(createMethodDropDown());
+
+        vbox.append(hbox);
+        vbox.append(createDrawingArea());
+        vbox.append(statusLabel);
+        vbox.setMarginTop(5);
+        vbox.setMarginBottom(5);
+        vbox.setMarginStart(5);
+        vbox.setMarginEnd(5);
+
+        loadDefaultImage();
+
+        demoWindow.setSizeRequest(SIZE, SIZE);
+        demoWindow.setChild(vbox);
+        return demoWindow;
+    }
+
+    private Widget createDrawingArea() {
+        drawingArea = new DrawingArea();
+        drawingArea.setHexpand(true);
+        drawingArea.setVexpand(true);
+
+        drawingArea.setDrawFunc((__self, drawing_area, cr, width, height, user_data) -> {
+            if (imageSurface != null) {
+                cr.save();
+                cr.setSourceSurface(imageSurface, 0, 0);
+                cr.paint();
+            }
+        }, null, null);
+        return drawingArea;
+    }
+
+    private Widget createMethodDropDown() {
+        var strs = new Strs(new String[]{"Cairo PNG", "Image Bridge"});
+        methodDropdown = DropDown.newFromStringsDropDown(strs);
+        return methodDropdown;
+    }
+
+    private Widget createLoadDefaultButton() {
+        var result = new Button();
+        result.setLabel("GTK.svg");
+        result.onClicked(()-> loadDefaultImage());
+        return result;
+    }
+
+    private Widget createSaveButton(Window parent) {
+        var result = new Button();
+        result.setLabel("Save…");
+        result.onClicked(()->{
+            var fileDialog = new FileDialog();
+            fileDialog.save(parent, null, (__self, source_object, res, data) -> {
+                try {
+                    saveImage(fileDialog.saveFinish(res));
+                } catch (AllocationError e) {
+                    statusLabel.setLabel(e.getMessage());
+                }
+            }, null);
+        });
+        return result;
+    }
+
+    private Widget createOpenButton(Window parent) {
+        var result = new Button();
+        result.setLabel("Open…");
+        result.onClicked(()->{
+            var fileDialog = new FileDialog();
+            fileDialog.open(parent, null, (__self, source_object, res, data) -> {
+                try {
+                    loadImage(fileDialog.openFinish(res));
+                } catch (AllocationError e) {
+                    statusLabel.setLabel(e.getMessage());
+                }
+            }, null);
+        });
+        return result;
+    }
+
+    private void loadDefaultImage() {
+        var path = "/GTK.svg";
+
+        try (InputStream inputStream = new JavaResource(path).asStream()) {
+            var start = System.currentTimeMillis();
+
+            var pixbuf =  Image.load(inputStream, SIZE, SIZE);
+            var surface = Cairo.imageSurfaceCreate(Format.ARGB32, SIZE, SIZE);
+            var context = surface.createContext();
+            Gdk.cairoSetSourcePixbuf(context,pixbuf,0,0);
+                context.paint();
+                pixbuf.unref();
+                var delta = System.currentTimeMillis() - start;
+
+            statusLabel.setLabel(delta + "ms: R " + path);
+            imageSurface = surface;
+            drawingArea.queueDraw();
+        } catch (IOException e) {
+            statusLabel.setLabel(e.getMessage());
+        }
+    }
+
+    private void saveImage(File file) {
+        if (file != null && file.isNotNull()) {
+            var path = file.getPath();
+            var start = System.currentTimeMillis();
+
+            if (methodDropdown.getSelected() == 0) {
+                imageSurface.writeToPng(path);
+            } else {
+                imageBridgeWrite(path.toString());
+            }
+
+            var delta = System.currentTimeMillis() - start;
+            statusLabel.setLabel(delta + "ms: W " + path);
+            path.destroy();
+        }
+    }
+
+    private void imageBridgeWrite(String path) {
+        try (OutputStream outputStream = new FileOutputStream(path)){
+            Pixbuf pixbuf = Gdk.pixbufGetFromSurface(imageSurface, 0, 0, imageSurface.getWidth(), imageSurface.getHeight());
+            Image.save(outputStream, pixbuf, "png");
+            pixbuf.unref();
+        } catch (IOException e) {
+            statusLabel.setText(e.getMessage());
+        }
+    }
+
+    private void loadImage(File file) {
+        if (file != null && file.isNotNull()) {
+            var path = file.getPath();
+
+            var start = System.currentTimeMillis();
+            Surface surface;
+
+            if (methodDropdown.getSelected() == 0) {
+                surface = Cairo.imageSurfaceCreateFromPng(path);
+            } else {
+                surface = imageBridgeRead(path.toString());
+            }
+
+            if (surface != null) {
+                var delta = System.currentTimeMillis() - start;
+                statusLabel.setLabel(delta + "ms: R " + path);
+                imageSurface = surface;
+                drawingArea.queueDraw();
+            }
+            path.destroy();
+        }
+    }
+
+    private Surface imageBridgeRead(String path) {
+        try (InputStream inputStream = new FileInputStream(path)) {
+            var pixbuf =  Image.load(inputStream);
+            var surface = Cairo.imageSurfaceCreate(Format.ARGB32, pixbuf.getWidth(), pixbuf.getHeight());
+            var context = surface.createContext();
+            Gdk.cairoSetSourcePixbuf(context,pixbuf,0,0);
+            context.paint();
+            pixbuf.unref();
+            return surface;
+        } catch (IOException e) {
+            statusLabel.setText(e.getMessage());
+        }
+        return null;
+    }
+
+    @Override
+    public Str getTitle() {
+        return TITLE;
+    }
+
+    @Override
+    public Str getDescription() {
+        return DESCRIPTION;
+    }
+}
diff --git a/examples/src/main/java/examples/libadwaita/layout/SplitViewDemo.java b/examples/src/main/java/examples/libadwaita/layout/SplitViewDemo.java
new file mode 100644
index 00000000..5995f670
--- /dev/null
+++ b/examples/src/main/java/examples/libadwaita/layout/SplitViewDemo.java
@@ -0,0 +1,124 @@
+package examples.libadwaita.layout;
+
+import ch.bailu.gtk.adw.Application;
+import ch.bailu.gtk.adw.ApplicationWindow;
+import ch.bailu.gtk.adw.Breakpoint;
+import ch.bailu.gtk.adw.BreakpointBin;
+import ch.bailu.gtk.adw.BreakpointCondition;
+import ch.bailu.gtk.adw.BreakpointConditionLengthType;
+import ch.bailu.gtk.adw.HeaderBar;
+import ch.bailu.gtk.adw.NavigationPage;
+import ch.bailu.gtk.adw.NavigationSplitView;
+import ch.bailu.gtk.gtk.Box;
+import ch.bailu.gtk.gtk.Button;
+import ch.bailu.gtk.gtk.Label;
+import ch.bailu.gtk.gtk.Orientation;
+import ch.bailu.gtk.gtk.PositionType;
+import ch.bailu.gtk.gtk.Unit;
+import ch.bailu.gtk.type.Str;
+import ch.bailu.gtk.type.Strs;
+
+public class SplitViewDemo {
+
+
+
+    public static void main(String[] args) {
+        var app = new Application(new Str("org.example.SplitViewDemo"), 0);
+
+        app.onActivate(() -> {
+            var headerBar = new HeaderBar();
+            var applicationWindow = new ApplicationWindow(app);
+            applicationWindow.setContent(createNavigationSplitView(applicationWindow, headerBar));
+            applicationWindow.present();
+            headerBar.setShowEndTitleButtons(true);
+        });
+
+        app.run(0, Strs.NULL);
+    }
+
+    private static NavigationSplitView createNavigationSplitView(ApplicationWindow applicationWindow, HeaderBar headerBar) {
+        var navigationSplitView = new NavigationSplitView();
+        var toLevel2Button = Button.newWithLabelButton("Show level 2");
+        var toLevel1Button = Button.newWithLabelButton("Show level 1");
+
+
+        var breakpoint = new Breakpoint(BreakpointCondition.newLengthBreakpointCondition(BreakpointConditionLengthType.MAX_WIDTH, 400d, Unit.POINTS));
+        breakpoint.onApply(() -> {
+            navigationSplitView.setCollapsed(true);
+            toLevel2Button.setVisible(true);
+            toLevel1Button.setVisible(true);
+        });
+        breakpoint.onUnapply(() -> {
+            navigationSplitView.setCollapsed(false);
+            toLevel2Button.setVisible(false);
+            toLevel1Button.setVisible(false);
+        });
+        applicationWindow.addBreakpoint(breakpoint);
+
+        toLevel1Button.onClicked(()->navigationSplitView.setShowContent(false));
+        toLevel2Button.onClicked(()->navigationSplitView.setShowContent(true));
+
+        navigationSplitView.setSidebar(createLeftPage(toLevel2Button, "Level 1", headerBar));
+        navigationSplitView.setContent(createRightPage(toLevel1Button, "Level 2 & 3"));
+        return navigationSplitView;
+    }
+
+    private static NavigationPage createRightPage(Button button, String title) {
+
+        var breakpointBin = new BreakpointBin();
+        var box = new Box(Orientation.VERTICAL, 0);
+        var navigationSplitView = new NavigationSplitView();
+        var toLevel3Button = Button.newWithLabelButton("Show level 3");
+        var toLevel2Button = Button.newWithLabelButton("Show level 2");
+
+
+        var breakpoint = new Breakpoint(BreakpointCondition.newLengthBreakpointCondition(BreakpointConditionLengthType.MAX_WIDTH, 400d, Unit.POINTS));
+        breakpoint.onApply(() -> {
+            navigationSplitView.setCollapsed(true);
+            toLevel3Button.setVisible(true);
+            toLevel2Button.setVisible(true);
+        });
+        breakpoint.onUnapply(() -> {
+            navigationSplitView.setCollapsed(false);
+            toLevel3Button.setVisible(false);
+            toLevel2Button.setVisible(false);
+        });
+
+        var headerBar = new HeaderBar();
+        System.out.println(headerBar.getDecorationLayout());
+        box.append(headerBar);
+
+        toLevel3Button.onClicked(()->navigationSplitView.setShowContent(true));
+        toLevel2Button.onClicked(()->navigationSplitView.setShowContent(false));
+
+        breakpointBin.addBreakpoint(breakpoint);
+        breakpointBin.setIntProperty("width-request", 100);
+        breakpointBin.setIntProperty("height-request", 100);
+        navigationSplitView.setContent(createInnerPage(toLevel2Button, "Level 3"));
+        navigationSplitView.setSidebar(createInnerPage(toLevel3Button, "Level 2"));
+
+        navigationSplitView.setSidebarPosition(PositionType.RIGHT);
+
+        box.append(navigationSplitView);
+        box.append(button);
+        breakpointBin.setChild(box);
+
+        return new NavigationPage(breakpointBin, title);
+    }
+
+    private static NavigationPage createInnerPage(Button button, String title) {
+        var box = new Box(Orientation.VERTICAL, 0);
+        box.append(new Label(title));
+        box.append(button);
+        return new NavigationPage(box, title);
+    }
+
+    private static NavigationPage createLeftPage(Button button, String title, HeaderBar headerBar) {
+        var box = new Box(Orientation.VERTICAL, 0);
+
+        box.append(headerBar);
+        box.append(new Label(title));
+        box.append(button);
+        return new NavigationPage(box, title);
+    }
+}
diff --git a/generator/src/main/resources/cairo-custom.gir b/generator/src/main/resources/cairo-custom.gir
index 1c97f7ca..93e0412f 100644
--- a/generator/src/main/resources/cairo-custom.gir
+++ b/generator/src/main/resources/cairo-custom.gir
@@ -743,6 +743,21 @@
                     </instance-parameter>
                 </parameters>
             </method>
+
+            <!-- https://cairographics.org/manual/cairo-PNG-Support.html -->
+            <method name = "write_to_png" c:identifier="cairo_surface_write_to_png">
+                <return-value transfer-ownership="none">
+                    <type name="Status" c:type="cairo_status_t"/>
+                </return-value>
+                <parameters>
+                    <instance-parameter name="imageSurface" transfer-ownership="none">
+                        <type name="Surface" c:type="cairo_surface_t*"/>
+                    </instance-parameter>
+                    <parameter name="filename" transfer-ownership="none">
+                        <type name="char*" c:type="char*"/>
+                    </parameter>
+                </parameters>
+            </method>
         </record>
 
 
@@ -1728,6 +1743,18 @@
                 </parameters>
         </function>
 
+        <!-- https://cairographics.org/manual/cairo-PNG-Support.html -->
+        <function name="image_surface_create_from_png" c:identifier="cairo_image_surface_create_from_png">
+            <return-value transfer-ownership="full">
+                <type name="Surface" c:type="cairo_surface_t*"/>
+            </return-value>
+
+            <parameters>
+                <parameter name="filename" transfer-ownership="none">
+                    <type name="char*" c:type="char*"/>
+                </parameter>
+            </parameters>
+        </function>
 
         <!-- custom -->
         <function name="image_surface_create_for_data" c:identifier="cairo_image_surface_create_for_data">
diff --git a/java-gtk/src/main/java/ch/bailu/gtk/gtk/ValueFactory.java b/java-gtk/src/main/java/ch/bailu/gtk/gtk/ValueFactory.java
index 06f1fd7b..9a79ce55 100644
--- a/java-gtk/src/main/java/ch/bailu/gtk/gtk/ValueFactory.java
+++ b/java-gtk/src/main/java/ch/bailu/gtk/gtk/ValueFactory.java
@@ -7,8 +7,11 @@
 import ch.bailu.gtk.type.Str;
 
 public class ValueFactory {
+    // TODO: This should come from SizeTable.kt
+    private static final int VALUE_SIZE = 24;
+
     public static Value initValue(long typeID) {
-        return new Value(new Record(5).cast()).init(typeID);
+        return new Value(new Record(VALUE_SIZE).cast()).init(typeID);
     }
 
     public static Value toValue(Str str) {
diff --git a/java-gtk/src/test/java/ch/bailu/gtk/TestPropertyAccess.java b/java-gtk/src/test/java/ch/bailu/gtk/TestPropertyAccess.java
index eec380d0..07cfbeb1 100644
--- a/java-gtk/src/test/java/ch/bailu/gtk/TestPropertyAccess.java
+++ b/java-gtk/src/test/java/ch/bailu/gtk/TestPropertyAccess.java
@@ -7,6 +7,7 @@
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.condition.EnabledIf;
 
+import ch.bailu.gtk.adw.BreakpointBin;
 import ch.bailu.gtk.gdk.Display;
 import ch.bailu.gtk.gio.ListStore;
 import ch.bailu.gtk.glib.Glib;
@@ -94,4 +95,17 @@ public void testPropertyAccessBox() {
         assertEquals(box.getCanFocus(), box.getBooleanProperty("homogeneous"));
         assertTrue(box.getHomogeneous());
     }
+
+    @Test
+    @EnabledIf("gtkInit")
+    public void testPropertyAccessBreakpointBin() {
+        var breakpointBin = new BreakpointBin();
+
+        for (int i=0; i< 10000; i++) {
+            breakpointBin.setIntProperty("width-request", i);
+            breakpointBin.setIntProperty("height-request", i);
+
+            assertEquals(i, breakpointBin.getIntProperty("width-request"));
+        }
+    }
 }