Move combo box selection update logic to handler (#19929)

Move logic related to updating the selection to the handler and
VFilterSelect.

Change-Id: I537d3cd23a3e990de1be578a506029c930c55da7

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

@@ -1487,14 +1487,6 @@ public class VFilterSelect extends Composite implements Field, KeyDownHandler,
             popupOpenerClicked = true;
         }
 
-        /**
-         * Returns true if the popup opener has been clicked. This method is for
-         * internal use only and will most likely be removed in the future.
-         */
-        public boolean isPopupOpenerClicked() {
-            return popupOpenerClicked;
-        }
-
         /**
          * Cancel a pending request to perform post-filtering actions.
          */
@@ -1540,6 +1532,46 @@ public class VFilterSelect extends Composite implements Field, KeyDownHandler,
                 suggestionPopup.menu.doPostFilterSelectedItemAction();
             }
         }
+
+        /**
+         * Perform selection (if appropriate) based on a reply from the server.
+         * When this method is called, the suggestions have been reset if new
+         * ones (different from the previous list) were received from the
+         * server.
+         * 
+         * @param selectedKey
+         *            new selected key or null if none given by the server
+         * @param selectedCaption
+         *            new selected item caption if sent by the server or null -
+         *            this is used when the selected item is not on the current
+         *            page
+         * @param oldSuggestionTextMatchTheOldSelection
+         *            true if the old filtering text box contents matched
+         *            exactly the old selection
+         */
+        public void updateSelectionFromServer(String selectedKey,
+                String selectedCaption,
+                boolean oldSuggestionTextMatchTheOldSelection) {
+            // when filtering with empty filter, server sets the selected key
+            // to "", which we don't select here. Otherwise we won't be able to
+            // reset back to the item that was selected before filtering
+            // started.
+            if (selectedKey != null && !selectedKey.equals("")) {
+                performSelection(selectedKey,
+                        oldSuggestionTextMatchTheOldSelection,
+                        !isWaitingForFilteringResponse() || popupOpenerClicked);
+            } else if (!isWaitingForFilteringResponse()
+                    && selectedCaption != null) {
+                // scrolling to correct page is disabled, caption is passed as a
+                // special parameter
+                tb.setText(selectedCaption);
+            } else {
+                if (!isWaitingForFilteringResponse() || popupOpenerClicked) {
+                    resetSelection();
+                }
+            }
+        }
+
     }
 
     @Deprecated
@@ -2040,6 +2072,85 @@ public class VFilterSelect extends Composite implements Field, KeyDownHandler,
         }
     }
 
+    /**
+     * Perform selection based on a message from the server.
+     * 
+     * This method is called when the server gave a non-empty selected item key,
+     * whereas null selection is handled by {@link #resetSelection()} and the
+     * special case where the selected item is not on the current page is
+     * handled separately by the caller.
+     * 
+     * @param selectedKey
+     *            non-empty selected item key
+     * @param oldSuggestionTextMatchTheOldSelection
+     *            true if the suggestion box text matched the previous selection
+     *            before the message from the server updating the selection
+     * @param updatePromptAndSelectionIfMatchFound
+     */
+    private void performSelection(String selectedKey,
+            boolean oldSuggestionTextMatchTheOldSelection,
+            boolean updatePromptAndSelectionIfMatchFound) {
+        // some item selected
+        for (FilterSelectSuggestion suggestion : currentSuggestions) {
+            String suggestionKey = suggestion.getOptionKey();
+            if (!suggestionKey.equals(selectedKey)) {
+                continue;
+            }
+            // at this point, suggestion key matches the new selection key
+            if (updatePromptAndSelectionIfMatchFound) {
+                if (!suggestionKey.equals(selectedOptionKey)
+                        || suggestion.getReplacementString().equals(
+                                tb.getText())
+                        || oldSuggestionTextMatchTheOldSelection) {
+                    // Update text field if we've got a new
+                    // selection
+                    // Also update if we've got the same text to
+                    // retain old text selection behavior
+                    // OR if selected item caption is changed.
+                    setPromptingOff(suggestion.getReplacementString());
+                    selectedOptionKey = suggestionKey;
+                }
+            }
+            currentSuggestion = suggestion;
+            setSelectedItemIcon(suggestion.getIconUri());
+            // only a single item can be selected
+            break;
+        }
+    }
+
+    /**
+     * Reset the selection of the combo box to an empty string if focused, the
+     * input prompt if not.
+     * 
+     * This method also clears the current suggestion and the selected option
+     * key.
+     */
+    private void resetSelection() {
+        // select nulled
+        if (!focused) {
+            /*
+             * client.updateComponent overwrites all styles so we must ALWAYS
+             * set the prompting style at this point, even though we think it
+             * has been set already...
+             */
+            setPromptingOff("");
+            if (enabled && !readonly) {
+                setPromptingOn();
+            }
+        } else {
+            // we have focus in field, prompting can't be set on,
+            // instead just clear the input if the value has changed from
+            // something else to null
+            if (selectedOptionKey != null
+                    || (allowNewItem && !tb.getValue().isEmpty())) {
+                tb.setValue("");
+            }
+        }
+        currentSuggestion = null; // #13217
+        setSelectedItemIcon(null);
+        selectedOptionKey = null;
+    }
+
     private void forceReflow() {
         WidgetUtil.setStyleTemporarily(tb.getElement(), "zoom", "1");
     }

client/src/main/java/com/vaadin/client/ui/combobox/ComboBoxConnector.java

@@ -47,10 +47,6 @@ public class ComboBoxConnector extends AbstractFieldConnector implements
     protected FocusAndBlurServerRpc focusAndBlurRpc = RpcProxy.create(
             FocusAndBlurServerRpc.class, this);
 
-    // oldSuggestionTextMatchTheOldSelection is used to detect when it's safe to
-    // update textbox text by a changed item caption.
-    private boolean oldSuggestionTextMatchTheOldSelection;
-
     private boolean immediate;
 
     @Override
@@ -152,10 +148,12 @@ public class ComboBoxConnector extends AbstractFieldConnector implements
         // popup. Popup needs to be repopulated with suggestions from UIDL.
         boolean popupOpenAndCleared = false;
 
-        oldSuggestionTextMatchTheOldSelection = false;
+        // oldSuggestionTextMatchTheOldSelection is used to detect when it's
+        // safe to update textbox text by a changed item caption.
+        boolean oldSuggestionTextMatchesTheOldSelection = false;
 
         if (suggestionsChanged) {
-            oldSuggestionTextMatchTheOldSelection = isWidgetsCurrentSelectionTextInTextBox();
+            oldSuggestionTextMatchesTheOldSelection = isWidgetsCurrentSelectionTextInTextBox();
             getWidget().currentSuggestions.clear();
 
             if (!getDataReceivedHandler().isWaitingForFilteringResponse()) {
@@ -191,24 +189,21 @@ public class ComboBoxConnector extends AbstractFieldConnector implements
         //
         ) {
 
+            // single selected key (can be empty string) or empty array for null
+            // selection
             String[] selectedKeys = uidl.getStringArrayVariable("selected");
-
-            // when filtering with empty filter, server sets the selected key
-            // to "", which we don't select here. Otherwise we won't be able to
-            // reset back to the item that was selected before filtering
-            // started.
-            if (selectedKeys.length > 0 && !selectedKeys[0].equals("")) {
-                performSelection(selectedKeys[0]);
-            } else if (!getDataReceivedHandler()
-                    .isWaitingForFilteringResponse()
-                    && uidl.hasAttribute("selectedCaption")) {
-                // scrolling to correct page is disabled, caption is passed as a
-                // special parameter
-                getWidget().tb.setText(uidl
-                        .getStringAttribute("selectedCaption"));
-            } else {
-                resetSelection();
+            String selectedKey = null;
+            if (selectedKeys.length == 1) {
+                selectedKey = selectedKeys[0];
             }
+            // selected item caption in case it is not on the current page
+            String selectedCaption = null;
+            if (uidl.hasAttribute("selectedCaption")) {
+                selectedCaption = uidl.getStringAttribute("selectedCaption");
+            }
+
+            getDataReceivedHandler().updateSelectionFromServer(selectedKey,
+                    selectedCaption, oldSuggestionTextMatchesTheOldSelection);
         }
 
         // TODO even this condition should probably be moved to the handler
@@ -241,72 +236,12 @@ public class ComboBoxConnector extends AbstractFieldConnector implements
         getDataReceivedHandler().serverReplyHandled();
     }
 
-    private void performSelection(String selectedKey) {
-        // some item selected
-        for (FilterSelectSuggestion suggestion : getWidget().currentSuggestions) {
-            String suggestionKey = suggestion.getOptionKey();
-            if (!suggestionKey.equals(selectedKey)) {
-                continue;
-            }
-            if (!getDataReceivedHandler().isWaitingForFilteringResponse()
-                    || getDataReceivedHandler().isPopupOpenerClicked()) {
-                if (!suggestionKey.equals(getWidget().selectedOptionKey)
-                        || suggestion.getReplacementString().equals(
-                                getWidget().tb.getText())
-                        || oldSuggestionTextMatchTheOldSelection) {
-                    // Update text field if we've got a new
-                    // selection
-                    // Also update if we've got the same text to
-                    // retain old text selection behavior
-                    // OR if selected item caption is changed.
-                    getWidget().setPromptingOff(
-                            suggestion.getReplacementString());
-                    getWidget().selectedOptionKey = suggestionKey;
-                }
-            }
-            getWidget().currentSuggestion = suggestion;
-            getWidget().setSelectedItemIcon(suggestion.getIconUri());
-            // only a single item can be selected
-            break;
-        }
-    }
-
     private boolean isWidgetsCurrentSelectionTextInTextBox() {
         return getWidget().currentSuggestion != null
                 && getWidget().currentSuggestion.getReplacementString().equals(
                         getWidget().tb.getText());
     }
 
-    private void resetSelection() {
-        if (!getDataReceivedHandler().isWaitingForFilteringResponse()
-                || getDataReceivedHandler().isPopupOpenerClicked()) {
-            // select nulled
-            if (!getWidget().focused) {
-                /*
-                 * client.updateComponent overwrites all styles so we must
-                 * ALWAYS set the prompting style at this point, even though we
-                 * think it has been set already...
-                 */
-                getWidget().setPromptingOff("");
-                if (getWidget().enabled && !getWidget().readonly) {
-                    getWidget().setPromptingOn();
-                }
-            } else {
-                // we have focus in field, prompting can't be set on, instead
-                // just clear the input if the value has changed from something
-                // else to null
-                if (getWidget().selectedOptionKey != null
-                        || (getWidget().allowNewItem && !getWidget().tb
-                                .getValue().isEmpty())) {
-                    getWidget().tb.setValue("");
-                }
-            }
-            getWidget().currentSuggestion = null; // #13217
-            getWidget().setSelectedItemIcon(null);
-            getWidget().selectedOptionKey = null;
-        }
-    }
-
     @Override
     public VFilterSelect getWidget() {
         return (VFilterSelect) super.getWidget();