Bug 1729402 - Changing inputmode might not set input-purpose on GTK. r=masayuki

I have to consider that we have to set input-purpose even if inputmode only
is changed.

Differential Revision: https://phabricator.services.mozilla.com/D125209

widget/IMEData.h

@@ -410,6 +410,25 @@ struct InputContext final {
            !mHTMLInputType.EqualsLiteral("email");
   }
 
+  bool IsInputAttributeChanged(const InputContext& aOldContext) const {
+    return mIMEState.mEnabled != aOldContext.mIMEState.mEnabled ||
+#if defined(ANDROID) || defined(MOZ_WIDGET_GTK) || defined(XP_WIN)
+           // input type and inputmode are supported by Windows IME API, GTK
+           // IME API and Android IME API
+           mHTMLInputType != aOldContext.mHTMLInputType ||
+           mHTMLInputInputmode != aOldContext.mHTMLInputInputmode ||
+#endif
+#if defined(ANDROID) || defined(MOZ_WIDGET_GTK)
+           // autocapitalize is supported by Android IME API and GTK IME API
+           mAutocapitalize != aOldContext.mAutocapitalize ||
+#endif
+#if defined(ANDROID)
+           // enterkeyhint is only supported by Android IME API.
+           mActionHint != aOldContext.mActionHint ||
+#endif
+           false;
+  }
+
   IMEState mIMEState;
 
   /* The type of the input if the input is a html input field */

widget/gtk/IMContextWrapper.cpp

@@ -1275,9 +1275,7 @@ void IMContextWrapper::SetInputContext(nsWindow* aCaller,
     return;
   }
 
-  bool changingEnabledState =
-      aContext->mIMEState.mEnabled != mInputContext.mIMEState.mEnabled ||
-      aContext->mHTMLInputType != mInputContext.mHTMLInputType;
+  bool changingEnabledState = aContext->IsInputAttributeChanged(mInputContext);
 
   // Release current IME focus if IME is enabled.
   if (changingEnabledState && mInputContext.mIMEState.IsEditable()) {