Add lightweight visual indication for numbers.

This change adds lightweight visual hints of alternate numeric characters on the top row - e.g. having a light gray '1' on the upper right corner of letter 'q'

Note that MDPI resources are tentative (the same as HDPI for now, until we get fixed MDPI visual assets).

bug: 3004632
Change-Id: I7a25cf90b702433a844c88f5c47bf914706af9bc

java/src/com/android/inputmethod/latin/LatinKeyboard.java

@@ -63,6 +63,9 @@ public class LatinKeyboard extends Keyboard {
     private Key mF1Key;
     private Key mSpaceKey;
     private Key m123Key;
+    private final int NUMBER_HINT_COUNT = 10;
+    private Key[] mNumberHintKeys;
+    private Drawable[] mNumberHintIcons = new Drawable[NUMBER_HINT_COUNT];
     private int mSpaceKeyIndex = -1;
     private int mSpaceDragStartX;
     private int mSpaceDragLastDiff;
@@ -129,6 +132,21 @@ public class LatinKeyboard extends Keyboard {
         mIsAlphaKeyboard = xmlLayoutResId == R.xml.kbd_qwerty
                 || xmlLayoutResId == R.xml.kbd_qwerty_black;
         mSpaceKeyIndex = indexOf(' ');
+        initializeNumberHintResources(context);
+    }
+
+    private void initializeNumberHintResources(Context context) {
+        final Resources res = context.getResources();
+        mNumberHintIcons[0] = res.getDrawable(R.drawable.keyboard_hint_0);
+        mNumberHintIcons[1] = res.getDrawable(R.drawable.keyboard_hint_1);
+        mNumberHintIcons[2] = res.getDrawable(R.drawable.keyboard_hint_2);
+        mNumberHintIcons[3] = res.getDrawable(R.drawable.keyboard_hint_3);
+        mNumberHintIcons[4] = res.getDrawable(R.drawable.keyboard_hint_4);
+        mNumberHintIcons[5] = res.getDrawable(R.drawable.keyboard_hint_5);
+        mNumberHintIcons[6] = res.getDrawable(R.drawable.keyboard_hint_6);
+        mNumberHintIcons[7] = res.getDrawable(R.drawable.keyboard_hint_7);
+        mNumberHintIcons[8] = res.getDrawable(R.drawable.keyboard_hint_8);
+        mNumberHintIcons[9] = res.getDrawable(R.drawable.keyboard_hint_9);
     }
 
     @Override
@@ -150,6 +168,23 @@ public class LatinKeyboard extends Keyboard {
             m123Label = key.label;
             break;
         }
+
+        // For number hints on the upper-right corner of key
+        if (mNumberHintKeys == null) {
+            // NOTE: This protected method is being called from the base class constructor before
+            // mNumberHintKeys gets initialized.
+            mNumberHintKeys = new Key[NUMBER_HINT_COUNT];
+        }
+        int hintNumber = -1;
+        if (LatinKeyboardBaseView.isNumberAtLeftmostPopupChar(key)) {
+            hintNumber = key.popupCharacters.charAt(0) - '0';
+        } else if (LatinKeyboardBaseView.isNumberAtRightmostPopupChar(key)) {
+            hintNumber = key.popupCharacters.charAt(key.popupCharacters.length() - 1) - '0';
+        }
+        if (hintNumber >= 0 && hintNumber <= 9) {
+            mNumberHintKeys[hintNumber] = key;
+        }
+
         return key;
     }
 
@@ -293,6 +328,7 @@ public class LatinKeyboard extends Keyboard {
         if (mSpaceKey != null) {
             updateSpaceBarForLocale(isAutoCompletion, isBlack);
         }
+        updateNumberHintKeys();
     }
 
     private void setDefaultBounds(Drawable drawable) {
@@ -340,6 +376,14 @@ public class LatinKeyboard extends Keyboard {
         return mSpaceKey;
     }
 
+    private void updateNumberHintKeys() {
+        for (int i = 0; i < mNumberHintKeys.length; ++i) {
+            if (mNumberHintKeys[i] != null) {
+                mNumberHintKeys[i].icon = mNumberHintIcons[i];
+            }
+        }
+    }
+
     private void updateSpaceBarForLocale(boolean isAutoCompletion, boolean isBlack) {
         // If application locales are explicitly selected.
         if (mLocale != null) {

java/src/com/android/inputmethod/latin/LatinKeyboardBaseView.java

@@ -797,6 +797,7 @@ public class LatinKeyboardBaseView extends View implements PointerTracker.UIProx
             canvas.translate(key.x + kbdPaddingLeft, key.y + kbdPaddingTop);
             keyBackground.draw(canvas);
 
+            boolean shouldDrawIcon = true;
             if (label != null) {
                 // For characters, use large font. For labels like "Done", use small font.
                 if (label.length() > 1 && key.codes.length < 2) {
@@ -817,14 +818,24 @@ public class LatinKeyboardBaseView extends View implements PointerTracker.UIProx
                     paint);
                 // Turn off drop shadow
                 paint.setShadowLayer(0, 0, 0, 0);
-            } else if (key.icon != null) {
+
+                // Usually don't draw icon if label is not null, but we draw icon for the number
+                // hint.
+                shouldDrawIcon = isNumberAtEdgeOfPopupChars(key);
+            }
+            if (key.icon != null && shouldDrawIcon) {
+                // Special handing for the upper-right number hint icons
+                final int drawableWidth = isNumberAtEdgeOfPopupChars(key) ?
+                        key.width : key.icon.getIntrinsicWidth();
+                final int drawableHeight = isNumberAtEdgeOfPopupChars(key) ?
+                        key.height : key.icon.getIntrinsicHeight();
+
                 final int drawableX = (key.width - padding.left - padding.right
-                                - key.icon.getIntrinsicWidth()) / 2 + padding.left;
+                        - drawableWidth) / 2 + padding.left;
                 final int drawableY = (key.height - padding.top - padding.bottom
-                        - key.icon.getIntrinsicHeight()) / 2 + padding.top;
+                        - drawableHeight) / 2 + padding.top;
                 canvas.translate(drawableX, drawableY);
-                key.icon.setBounds(0, 0,
-                        key.icon.getIntrinsicWidth(), key.icon.getIntrinsicHeight());
+                key.icon.setBounds(0, 0, drawableWidth, drawableHeight);
                 key.icon.draw(canvas);
                 canvas.translate(-drawableX, -drawableY);
             }
@@ -885,7 +896,8 @@ public class LatinKeyboardBaseView extends View implements PointerTracker.UIProx
         Key key = tracker.getKey(keyIndex);
         if (key == null)
             return;
-        if (key.icon != null) {
+        // Should not draw number hint icons
+        if (key.icon != null && !isNumberAtEdgeOfPopupChars(key)) {
             mPreviewText.setCompoundDrawables(null, null, null,
                     key.iconPreview != null ? key.iconPreview : key.icon);
             mPreviewText.setText(null);
@@ -1100,12 +1112,8 @@ public class LatinKeyboardBaseView extends View implements PointerTracker.UIProx
         }
 
         // HACK: Have the leftmost number in the popup characters right above the key
-        boolean isNumberAtLeftmost = false;
-        if (popupKey.popupCharacters != null && popupKey.popupCharacters.length() > 1) {
-            char leftmostChar = popupKey.popupCharacters.charAt(0);
-            isNumberAtLeftmost = leftmostChar >= '0' && leftmostChar <= '9';
-        }
-
+        boolean isNumberAtLeftmost =
+                hasMultiplePopupChars(popupKey) && isNumberAtLeftmostPopupChar(popupKey);
         int popupX = popupKey.x + mWindowOffset[0];
         int popupY = popupKey.y + mWindowOffset[1];
         if (isNumberAtLeftmost) {
@@ -1151,6 +1159,37 @@ public class LatinKeyboardBaseView extends View implements PointerTracker.UIProx
         return true;
     }
 
+    private static boolean hasMultiplePopupChars(Key key) {
+        if (key.popupCharacters != null && key.popupCharacters.length() > 1) {
+            return true;
+        }
+        return false;
+    }
+
+    private static boolean isNumberAtEdgeOfPopupChars(Key key) {
+        return isNumberAtLeftmostPopupChar(key) || isNumberAtRightmostPopupChar(key);
+    }
+
+    /* package */ static boolean isNumberAtLeftmostPopupChar(Key key) {
+        if (key.popupCharacters != null && key.popupCharacters.length() > 0
+                && isAsciiDigit(key.popupCharacters.charAt(0))) {
+            return true;
+        }
+        return false;
+    }
+
+    /* package */ static boolean isNumberAtRightmostPopupChar(Key key) {
+        if (key.popupCharacters != null && key.popupCharacters.length() > 0
+                && isAsciiDigit(key.popupCharacters.charAt(key.popupCharacters.length() - 1))) {
+            return true;
+        }
+        return false;
+    }
+
+    private static boolean isAsciiDigit(char c) {
+        return (c < 0x80) && Character.isDigit(c);
+    }
+
     private MotionEvent generateMiniKeyboardMotionEvent(int action, int x, int y, long eventTime) {
         return MotionEvent.obtain(mMiniKeyboardPopupTime, eventTime, action,
                     x - mMiniKeyboardOriginX, y - mMiniKeyboardOriginY, 0);

java/src/com/android/inputmethod/latin/LatinKeyboardView.java

@@ -24,6 +24,7 @@ import android.inputmethodservice.Keyboard.Key;
 import android.os.Handler;
 import android.os.Message;
 import android.os.SystemClock;
+import android.text.TextUtils;
 import android.util.AttributeSet;
 import android.view.MotionEvent;
 
@@ -101,7 +102,7 @@ public class LatinKeyboardView extends LatinKeyboardBaseView {
         if (keyboard.isShifted()
                 && keyboard instanceof LatinKeyboard
                 && ((LatinKeyboard) keyboard).isAlphaKeyboard()
-                && label != null && label.length() < 3
+                && !TextUtils.isEmpty(label) && label.length() < 3
                 && Character.isLowerCase(label.charAt(0))) {
             label = label.toString().toUpperCase();
         }