Backport fix for #16992 to Vaadin 7.5.

Change-Id: I4899aac895f061cffffaccc5b0e33f92bada28b0

3 files changed, 56 insertions, 11 deletions

diff --git a/client/src/com/vaadin/client/ApplicationConnection.java b/client/src/com/vaadin/client/ApplicationConnection.java
index 5547b02895..24cfdf62b9 100644
--- a/client/src/com/vaadin/client/ApplicationConnection.java
+++ b/client/src/com/vaadin/client/ApplicationConnection.java
@@ -63,7 +63,6 @@ import com.google.gwt.user.client.Window.ClosingHandler;
 import com.google.gwt.user.client.ui.HasWidgets;
 import com.google.gwt.user.client.ui.Widget;
 import com.vaadin.client.ApplicationConfiguration.ErrorMessage;
-import com.vaadin.client.ApplicationConnection.ApplicationStoppedEvent;
 import com.vaadin.client.ResourceLoader.ResourceLoadEvent;
 import com.vaadin.client.ResourceLoader.ResourceLoadListener;
 import com.vaadin.client.communication.HasJavaScriptConnectorHelper;
@@ -1693,18 +1692,20 @@ public class ApplicationConnection implements HasHandlers {
 
                 updatingState = false;
 
-                if (!onlyNoLayoutUpdates) {
-                    Profiler.enter("Layout processing");
-                    try {
-                        LayoutManager layoutManager = getLayoutManager();
+                Profiler.enter("Layout processing");
+                try {
+                    LayoutManager layoutManager = getLayoutManager();
+                    if (!onlyNoLayoutUpdates) {
                         layoutManager.setEverythingNeedsMeasure();
+                    }
+                    if (layoutManager.isLayoutNeeded()) {
                         layoutManager.layoutNow();
-                    } catch (final Throwable e) {
-                        getLogger().log(Level.SEVERE,
-                                "Error processing layouts", e);
                     }
-                    Profiler.leave("Layout processing");
+                } catch (final Throwable e) {
+                    getLogger()
+                            .log(Level.SEVERE, "Error processing layouts", e);
                 }
+                Profiler.leave("Layout processing");
 
                 if (ApplicationConfiguration.isDebugMode()) {
                     Profiler.enter("Dumping state changes to the console");
diff --git a/client/src/com/vaadin/client/LayoutManager.java b/client/src/com/vaadin/client/LayoutManager.java
index 102e618f5e..2d10d0c082 100644
--- a/client/src/com/vaadin/client/LayoutManager.java
+++ b/client/src/com/vaadin/client/LayoutManager.java
@@ -1800,4 +1800,25 @@ public class LayoutManager {
         return Logger.getLogger(LayoutManager.class.getName());
     }
 
+    /**
+     * Checks if there is something waiting for a layout to take place.
+     * 
+     * @since 7.5.6
+     * @return true if there are connectors waiting for measurement or layout,
+     *         false otherwise
+     */
+    public boolean isLayoutNeeded() {
+        if (!needsHorizontalLayout.isEmpty() || !needsVerticalLayout.isEmpty()) {
+            return true;
+        }
+        if (!needsMeasure.isEmpty()) {
+            return true;
+        }
+
+        if (everythingNeedsMeasure) {
+            return true;
+        }
+
+        return false;
+    }
 }
diff --git a/client/src/com/vaadin/client/ui/layout/LayoutDependencyTree.java b/client/src/com/vaadin/client/ui/layout/LayoutDependencyTree.java
index 07bb6688e3..a4c5668948 100644
--- a/client/src/com/vaadin/client/ui/layout/LayoutDependencyTree.java
+++ b/client/src/com/vaadin/client/ui/layout/LayoutDependencyTree.java
@@ -17,6 +17,7 @@ package com.vaadin.client.ui.layout;
 
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.logging.Logger;
 
 import com.google.gwt.core.client.JsArrayString;
 import com.vaadin.client.ApplicationConnection;
@@ -500,6 +501,12 @@ public class LayoutDependencyTree {
             if (connector == null) {
                 connector = (ComponentConnector) ConnectorMap.get(connection)
                         .getConnector(connectorId);
+                if (connector == null) {
+                    getLogger().warning(
+                            "No connector found for id " + connectorId
+                                    + " while creating LayoutDependency");
+                    return null;
+                }
             }
             dependency = new LayoutDependency(connector, direction);
             dependencies.put(connectorId, dependency);
@@ -531,7 +538,12 @@ public class LayoutDependencyTree {
 
     public void setNeedsHorizontalLayout(String connectorId, boolean needsLayout) {
         LayoutDependency dependency = getDependency(connectorId, HORIZONTAL);
-        dependency.setNeedsLayout(needsLayout);
+        if (dependency != null) {
+            dependency.setNeedsLayout(needsLayout);
+        } else {
+            getLogger().warning(
+                    "No dependency found in setNeedsHorizontalLayout");
+        }
     }
 
     /**
@@ -549,7 +561,13 @@ public class LayoutDependencyTree {
 
     public void setNeedsVerticalLayout(String connectorId, boolean needsLayout) {
         LayoutDependency dependency = getDependency(connectorId, VERTICAL);
-        dependency.setNeedsLayout(needsLayout);
+        if (dependency != null) {
+            dependency.setNeedsLayout(needsLayout);
+        } else {
+            getLogger()
+                    .warning("No dependency found in setNeedsVerticalLayout");
+        }
+
     }
 
     public void markAsHorizontallyLayouted(ManagedLayout layout) {
@@ -736,4 +754,9 @@ public class LayoutDependencyTree {
         }
         return dependency.scrollingBoundary;
     }
+
+    private static Logger getLogger() {
+        return Logger.getLogger(LayoutDependencyTree.class.getName());
+    }
+
 }