Fix issue space key preview remains on screen and would not dismiss

The space key preview should be displayed one of the following case.
- Popup preview is enabled
- Language switcher is in action, whether popup preview is enabled or
  not.

For phone number keyboard, popup preview is never displayed even if
popup preview is enabled.

Bug: 3006612
Bug: 3021091
Change-Id: I5385c776d0e8e3981fc8d8851db9140d92599ce5

1 files changed, 11 insertions, 2 deletions

diff --git a/java/src/com/android/inputmethod/latin/LatinKeyboardBaseView.java b/java/src/com/android/inputmethod/latin/LatinKeyboardBaseView.java
index 26b3c0581..fd25d7521 100644
--- a/java/src/com/android/inputmethod/latin/LatinKeyboardBaseView.java
+++ b/java/src/com/android/inputmethod/latin/LatinKeyboardBaseView.java
@@ -881,8 +881,17 @@ public class LatinKeyboardBaseView extends View implements PointerTracker.UIProx
     public void showPreview(int keyIndex, PointerTracker tracker) {
         int oldKeyIndex = mOldPreviewKeyIndex;
         mOldPreviewKeyIndex = keyIndex;
-        // If key changed and preview is on ...
-        if (oldKeyIndex != keyIndex && mShowPreview) {
+        final boolean isLanguageSwitchEnabled = (mKeyboard instanceof LatinKeyboard)
+                && ((LatinKeyboard)mKeyboard).isLanguageSwitchEnabled();
+        // We should re-draw popup preview when 1) we need to hide the preview, 2) we will show
+        // the space key preview and 3) pointer moves off the space key to other letter key, we
+        // should hide the preview of the previous key.
+        final boolean hidePreviewOrShowSpaceKeyPreview = (tracker == null)
+                || tracker.isSpaceKey(keyIndex) || tracker.isSpaceKey(oldKeyIndex);
+        // If key changed and preview is on or the key is space (language switch is enabled)
+        if (oldKeyIndex != keyIndex
+                && (mShowPreview
+                        || (hidePreviewOrShowSpaceKeyPreview && isLanguageSwitchEnabled))) {
             if (keyIndex == NOT_A_KEY) {
                 mHandler.cancelPopupPreview();
                 mHandler.dismissPreview(DELAY_AFTER_PREVIEW);