Added partial support for the callback-selection-changed JS callback

- Editor is notified when the focused field (title or content) changes
- Handled disabling the format bar when the title is in focus

Author: aforcier

WordPressEditor/src/main/java/org/wordpress/android/editor/EditorFragment.java

@@ -34,7 +34,17 @@ public class EditorFragment extends EditorFragmentAbstract implements View.OnCli
 
     private static final String JS_CALLBACK_HANDLER = "nativeCallbackHandler";
 
+    private static final String TAG_FORMAT_BAR_BUTTON_MEDIA = "media";
     private static final String TAG_FORMAT_BAR_BUTTON_BOLD = "bold";
+    private static final String TAG_FORMAT_BAR_BUTTON_ITALIC = "italic";
+    private static final String TAG_FORMAT_BAR_BUTTON_QUOTE = "blockquote";
+    private static final String TAG_FORMAT_BAR_BUTTON_UL = "unorderedList";
+    private static final String TAG_FORMAT_BAR_BUTTON_OL = "orderedList";
+    private static final String TAG_FORMAT_BAR_BUTTON_LINK = "link";
+    private static final String TAG_FORMAT_BAR_BUTTON_HTML = "html";
+
+    private static final float TOOLBAR_ALPHA_ENABLED = 1;
+    private static final float TOOLBAR_ALPHA_DISABLED = 0.5f;
 
     private String mParamTitle;
     private String mParamContent;
@@ -72,10 +82,34 @@ public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle sa
         mWebView = (EditorWebView) view.findViewById(R.id.webview);
         initWebView();
 
-        ToggleButton boldButton = (ToggleButton) view.findViewById(R.id.bold);
-        boldButton.setOnClickListener(this);
+        ToggleButton mediaButton = (ToggleButton) view.findViewById(R.id.format_bar_button_media);
+        mTagToggleButtonMap.put(TAG_FORMAT_BAR_BUTTON_MEDIA, mediaButton);
+
+        ToggleButton boldButton = (ToggleButton) view.findViewById(R.id.format_bar_button_bold);
         mTagToggleButtonMap.put(TAG_FORMAT_BAR_BUTTON_BOLD, boldButton);
 
+        ToggleButton italicButton = (ToggleButton) view.findViewById(R.id.format_bar_button_italic);
+        mTagToggleButtonMap.put(TAG_FORMAT_BAR_BUTTON_ITALIC, italicButton);
+
+        ToggleButton quoteButton = (ToggleButton) view.findViewById(R.id.format_bar_button_quote);
+        mTagToggleButtonMap.put(TAG_FORMAT_BAR_BUTTON_QUOTE, quoteButton);
+
+        ToggleButton ulButton = (ToggleButton) view.findViewById(R.id.format_bar_button_ul);
+        mTagToggleButtonMap.put(TAG_FORMAT_BAR_BUTTON_UL, ulButton);
+
+        ToggleButton olButton = (ToggleButton) view.findViewById(R.id.format_bar_button_ol);
+        mTagToggleButtonMap.put(TAG_FORMAT_BAR_BUTTON_OL, olButton);
+
+        ToggleButton linkButton = (ToggleButton) view.findViewById(R.id.format_bar_button_link);
+        mTagToggleButtonMap.put(TAG_FORMAT_BAR_BUTTON_LINK, linkButton);
+
+        ToggleButton htmlButton = (ToggleButton) view.findViewById(R.id.format_bar_button_html);
+        mTagToggleButtonMap.put(TAG_FORMAT_BAR_BUTTON_HTML, htmlButton);
+
+        for (ToggleButton button : mTagToggleButtonMap.values()) {
+            button.setOnClickListener(this);
+        }
+
         return view;
     }
 
@@ -200,4 +234,31 @@ public void run() {
             }
         });
     }
+
+    public void onSelectionChanged(final Map<String, String> selectionArgs) {
+        final String id = selectionArgs.get("id"); // The field currently in focus
+        mWebView.post(new Runnable() {
+            @Override
+            public void run() {
+                if (!id.isEmpty()) {
+                    switch(id) {
+                        case "zss_field_title":
+                            updateToolbarEnabledState(false);
+                            break;
+                        case "zss_field_content":
+                            updateToolbarEnabledState(true);
+                            break;
+                    }
+                }
+            }
+        });
+    }
+
+    void updateToolbarEnabledState(boolean enabled) {
+        float alpha = (enabled ? TOOLBAR_ALPHA_ENABLED : TOOLBAR_ALPHA_DISABLED);
+        for(ToggleButton button : mTagToggleButtonMap.values()) {
+            button.setEnabled(enabled);
+            button.setAlpha(alpha);
+        }
+    }
 }

WordPressEditor/src/main/java/org/wordpress/android/editor/JsCallbackReceiver.java

@@ -48,8 +48,11 @@ public void executeCallback(String callbackId, String params) {
                 mPreviousStyleSet = newStyleSet;
                 break;
             case CALLBACK_SELECTION_CHANGED:
-                // Called when changes are made to selection (includes moving the caret without selecting text)
+                // Called for changes to the field in current focus and for changes made to selection
+                // (includes moving the caret without selecting text)
                 // TODO: Possibly needed for handling WebView scrolling when caret moves (from iOS)
+                Set<String> selectionKeyValueSet = Utils.splitDelimitedString(params, JS_CALLBACK_DELIMITER);
+                mListener.onSelectionChanged(Utils.buildMapFromKeyValuePairs(selectionKeyValueSet));
                 break;
             case CALLBACK_INPUT:
                 // Called on key press

WordPressEditor/src/main/java/org/wordpress/android/editor/OnJsEditorStateChangedListener.java

@@ -4,5 +4,6 @@
 
 public interface OnJsEditorStateChangedListener {
     void onDomLoaded();
+    void onSelectionChanged(Map<String, String> selectionArgs);
     void onSelectionStyleChanged(Map<String, Boolean> changeSet);
 }

WordPressEditor/src/main/java/org/wordpress/android/editor/Utils.java

@@ -66,6 +66,20 @@ public static Set<String> splitDelimitedString(String string, String delimiter)
         return splitString;
     }
 
+    /**
+     * Accepts a set of strings, each string being a key-value pair (<code>id=5</code>,
+     * <code>name=content-filed</code>). Returns a map of all the key-value pairs in the set.
+     * @param keyValueSet the set of key-value pair strings
+     */
+    public static Map<String, String> buildMapFromKeyValuePairs(Set<String> keyValueSet) {
+        Map<String, String> selectionArgs = new HashMap<>();
+        for (String pair : keyValueSet) {
+            String[] splitString = pair.split("=");
+            selectionArgs.put(splitString[0], splitString[1]);
+        }
+        return selectionArgs;
+    }
+
     /**
      * Compares two <code>Sets</code> and returns a <code>Map</code> of elements not contained in both
      * <code>Sets</code>. Elements contained in <code>oldSet</code> but not in <code>newSet</code> will be marked