Add warning message if developer depends on undocumented behavior

Bug: 371894731
Test: Manually done
Flag: com.android.text.flags.typeface_redesign_readonly
Change-Id: I375e8dd6bf5e04be4819c2e9146473cb02df409a

2 files changed, 26 insertions, 2 deletions

diff --git a/graphics/java/android/graphics/Paint.java b/graphics/java/android/graphics/Paint.java
index 2e885145819c..50c95a9fa882 100644
--- a/graphics/java/android/graphics/Paint.java
+++ b/graphics/java/android/graphics/Paint.java
@@ -1586,6 +1586,18 @@ public class Paint {
      * @return         typeface
      */
     public Typeface setTypeface(Typeface typeface) {
+        if (Flags.typefaceRedesignReadonly() && typeface != null
+                && typeface.isVariationInstance()) {
+            Log.w(TAG, "Attempting to set a Typeface on a Paint object that was previously "
+                    + "configured with setFontVariationSettings(). This is no longer supported as "
+                    + "of Target SDK " + Build.VERSION_CODES.BAKLAVA + ". To apply font"
+                    + " variations, call setFontVariationSettings() directly on the Paint object"
+                    + " instead.");
+        }
+        return setTypefaceWithoutWarning(typeface);
+    }
+
+    private Typeface setTypefaceWithoutWarning(Typeface typeface) {
         final long typefaceNative = typeface == null ? 0 : typeface.native_instance;
         nSetTypeface(mNativePaint, typefaceNative);
         mTypeface = typeface;
@@ -2183,7 +2195,7 @@ public class Paint {
 
         if (settings == null || settings.length() == 0) {
             mFontVariationSettings = null;
-            setTypeface(Typeface.createFromTypefaceWithVariation(mTypeface,
+            setTypefaceWithoutWarning(Typeface.createFromTypefaceWithVariation(mTypeface,
                       Collections.emptyList()));
             return true;
         }
@@ -2202,7 +2214,8 @@ public class Paint {
             return false;
         }
         mFontVariationSettings = settings;
-        setTypeface(Typeface.createFromTypefaceWithVariation(targetTypeface, filteredAxes));
+        setTypefaceWithoutWarning(
+                Typeface.createFromTypefaceWithVariation(targetTypeface, filteredAxes));
         return true;
     }
 
diff --git a/graphics/java/android/graphics/Typeface.java b/graphics/java/android/graphics/Typeface.java
index 889a778556b7..874b847c709c 100644
--- a/graphics/java/android/graphics/Typeface.java
+++ b/graphics/java/android/graphics/Typeface.java
@@ -237,6 +237,8 @@ public class Typeface {
 
     private @IntRange(from = 0, to = FontStyle.FONT_WEIGHT_MAX) final int mWeight;
 
+    private boolean mIsVariationInstance;
+
     // Value for weight and italic. Indicates the value is resolved by font metadata.
     // Must be the same as the C++ constant in core/jni/android/graphics/FontFamily.cpp
     /** @hide */
@@ -279,6 +281,11 @@ public class Typeface {
         return mWeight;
     }
 
+    /** @hide */
+    public boolean isVariationInstance() {
+        return mIsVariationInstance;
+    }
+
     /** Returns the typeface's intrinsic style attributes */
     public @Style int getStyle() {
         return mStyle;
@@ -1280,6 +1287,7 @@ public class Typeface {
         mCleaner = sRegistry.registerNativeAllocation(this, native_instance);
         mStyle = nativeGetStyle(ni);
         mWeight = nativeGetWeight(ni);
+        mIsVariationInstance = nativeIsVariationInstance(ni);
         mSystemFontFamilyName = systemFontFamilyName;
         mDerivedFrom = derivedFrom;
     }
@@ -1698,6 +1706,9 @@ public class Typeface {
     private static native int  nativeGetWeight(long nativePtr);
 
     @CriticalNative
+    private static native boolean nativeIsVariationInstance(long nativePtr);
+
+    @CriticalNative
     private static native long nativeGetReleaseFunc();
 
     private static native void nativeRegisterGenericFamily(String str, long nativePtr);