Remove redundant null checks before an instanceof (#10173)

client/src/main/java/com/vaadin/client/Util.java

@@ -1249,8 +1249,7 @@ public class Util {
     private static HasChildMeasurementHintConnector getPossibleChildMeasurementHintParentConnector(
             ComponentConnector candidate) {
         ServerConnector parent = candidate.getParent();
-        if (parent != null
-                && parent instanceof HasChildMeasurementHintConnector) {
+        if (parent instanceof HasChildMeasurementHintConnector) {
             return (HasChildMeasurementHintConnector) parent;
         }
         return null;

client/src/main/java/com/vaadin/client/ui/VAbstractCalendarPanel.java

@@ -247,8 +247,7 @@ public abstract class VAbstractCalendarPanel<R extends Enum<R>>
                     int cellCount = days.getCellCount(i);
                     for (int j = 0; j < cellCount; j++) {
                         Widget widget = days.getWidget(i, j);
-                        if (widget != null
-                                && widget instanceof VAbstractCalendarPanel.Day) {
+                        if (widget instanceof VAbstractCalendarPanel.Day) {
                             Day curday = (Day) widget;
                             if (curday.getDate().equals(date)) {
                                 curday.addStyleDependentName(CN_FOCUSED);
@@ -358,8 +357,7 @@ public abstract class VAbstractCalendarPanel<R extends Enum<R>>
             int cellCount = days.getCellCount(i);
             for (int j = 0; j < cellCount; j++) {
                 Widget widget = days.getWidget(i, j);
-                if (widget != null
-                        && widget instanceof VAbstractCalendarPanel.Day) {
+                if (widget instanceof VAbstractCalendarPanel.Day) {
                     Day curday = (Day) widget;
                     if (curday.getDate().equals(date)) {
                         curday.addStyleDependentName(CN_SELECTED);

compatibility-server/src/main/java/com/vaadin/v7/data/util/FilesystemContainer.java

@@ -676,7 +676,7 @@ public class FilesystemContainer implements Container.Hierarchical {
          */
         @Override
         public boolean equals(Object obj) {
-            if (obj == null || !(obj instanceof FileItem)) {
+            if (!(obj instanceof FileItem)) {
                 return false;
             }
             final FileItem fi = (FileItem) obj;

compatibility-server/src/main/java/com/vaadin/v7/data/util/PropertysetItem.java

@@ -325,7 +325,7 @@ public class PropertysetItem
     @Override
     public boolean equals(Object obj) {
 
-        if (obj == null || !(obj instanceof PropertysetItem)) {
+        if (!(obj instanceof PropertysetItem)) {
             return false;
         }
 

compatibility-server/src/main/java/com/vaadin/v7/data/util/sqlcontainer/RowItem.java

@@ -65,7 +65,7 @@ public final class RowItem implements Item {
 
     @Override
     public Property getItemProperty(Object id) {
-        if (id instanceof String && id != null) {
+        if (id instanceof String) {
             for (ColumnProperty cp : properties) {
                 if (id.equals(cp.getPropertyId())) {
                     return cp;

compatibility-server/src/main/java/com/vaadin/v7/data/validator/DoubleValidator.java

@@ -59,7 +59,7 @@ public class DoubleValidator extends AbstractStringValidator {
 
     @Override
     public void validate(Object value) throws InvalidValueException {
-        if (value != null && value instanceof Double) {
+        if (value instanceof Double) {
             // Allow Doubles to pass through the validator for easier
             // migration. Otherwise a TextField connected to an double property
             // with a DoubleValidator will fail.

compatibility-server/src/main/java/com/vaadin/v7/data/validator/IntegerValidator.java

@@ -60,7 +60,7 @@ public class IntegerValidator extends AbstractStringValidator {
 
     @Override
     public void validate(Object value) throws InvalidValueException {
-        if (value != null && value instanceof Integer) {
+        if (value instanceof Integer) {
             // Allow Integers to pass through the validator for easier
             // migration. Otherwise a TextField connected to an integer property
             // with an IntegerValidator will fail.

compatibility-server/src/main/java/com/vaadin/v7/ui/AbstractSelect.java

@@ -1939,8 +1939,7 @@ public abstract class AbstractSelect extends AbstractField<Object> implements
                 if (pids != null) {
                     for (Object id : pids) {
                         Property<?> p = i.getItemProperty(id);
-                        if (p != null
-                                && p instanceof Property.ValueChangeNotifier) {
+                        if (p instanceof Property.ValueChangeNotifier) {
                             ((Property.ValueChangeNotifier) p)
                                     .addValueChangeListener(
                                             getCaptionChangeListener());
@@ -1953,7 +1952,7 @@ public abstract class AbstractSelect extends AbstractField<Object> implements
             case PROPERTY:
                 final Property<?> p = getContainerProperty(itemId,
                         getItemCaptionPropertyId());
-                if (p != null && p instanceof Property.ValueChangeNotifier) {
+                if (p instanceof Property.ValueChangeNotifier) {
                     ((Property.ValueChangeNotifier) p)
                             .addValueChangeListener(getCaptionChangeListener());
                     captionChangeNotifiers.add(p);
@@ -1964,7 +1963,7 @@ public abstract class AbstractSelect extends AbstractField<Object> implements
             if (getItemIconPropertyId() != null) {
                 final Property p = getContainerProperty(itemId,
                         getItemIconPropertyId());
-                if (p != null && p instanceof Property.ValueChangeNotifier) {
+                if (p instanceof Property.ValueChangeNotifier) {
                     ((Property.ValueChangeNotifier) p)
                             .addValueChangeListener(getCaptionChangeListener());
                     captionChangeNotifiers.add(p);

server/src/main/java/com/vaadin/server/DragAndDropService.java

@@ -215,7 +215,7 @@ public class DragAndDropService implements VariableOwner, ClientConnector {
         variables = (Map<String, Object>) variables.get("tra");
 
         Transferable transferable = null;
-        if (sourceComponent != null && sourceComponent instanceof DragSource) {
+        if (sourceComponent instanceof DragSource) {
             transferable = ((DragSource) sourceComponent)
                     .getTransferable(variables);
         }

server/src/main/java/com/vaadin/server/communication/PushRequestHandler.java

@@ -141,7 +141,7 @@ public class PushRequestHandler
                 .getAttributeName(vaadinServletConfig.getServletName());
         Object framework = vaadinServletConfig.getServletContext()
                 .getAttribute(attributeName);
-        if (framework != null && framework instanceof AtmosphereFramework) {
+        if (framework instanceof AtmosphereFramework) {
             return (AtmosphereFramework) framework;
         }
 

server/src/main/java/com/vaadin/ui/Grid.java

@@ -1966,7 +1966,7 @@ public class Grid<T> extends AbstractListing<T> implements HasComponents,
 
             // Remove old renderer
             Connector oldRenderer = getState().renderer;
-            if (oldRenderer != null && oldRenderer instanceof Extension) {
+            if (oldRenderer instanceof Extension) {
                 removeExtension((Extension) oldRenderer);
             }