[Feature] Add warning inside setIndeterminate().

library/src/main/java/me/zhanghai/android/materialprogressbar/HorizontalProgressDrawable.java

@@ -24,7 +24,7 @@
  * A backported {@code Drawable} for determinate horizontal {@code ProgressBar}.
  */
 public class HorizontalProgressDrawable extends LayerDrawable implements IntrinsicPaddingDrawable,
-        ShowBackgroundDrawable, TintableDrawable {
+        MaterialProgressDrawable, ShowBackgroundDrawable, TintableDrawable {
 
     private static final String TAG = HorizontalProgressDrawable.class.getSimpleName();
 

library/src/main/java/me/zhanghai/android/materialprogressbar/IndeterminateHorizontalProgressDrawable.java

@@ -18,7 +18,7 @@
  * A backported {@code Drawable} for indeterminate horizontal {@code ProgressBar}.
  */
 public class IndeterminateHorizontalProgressDrawable extends BaseIndeterminateProgressDrawable
-        implements ShowBackgroundDrawable {
+        implements MaterialProgressDrawable, ShowBackgroundDrawable {
 
     private static final int PROGRESS_INTRINSIC_HEIGHT_DP = 4;
     private static final int PADDED_INTRINSIC_HEIGHT_DP = 16;

library/src/main/java/me/zhanghai/android/materialprogressbar/IndeterminateProgressDrawable.java

@@ -15,7 +15,8 @@
 /**
  * A backported {@code Drawable} for indeterminate circular {@code ProgressBar}.
  */
-public class IndeterminateProgressDrawable extends BaseIndeterminateProgressDrawable {
+public class IndeterminateProgressDrawable extends BaseIndeterminateProgressDrawable
+        implements MaterialProgressDrawable {
 
     private static final int PROGRESS_INTRINSIC_SIZE_DP = 42;
     private static final int PADDED_INTRINSIC_SIZE_DP = 48;

library/src/main/java/me/zhanghai/android/materialprogressbar/MaterialProgressBar.java

@@ -31,8 +31,10 @@ public class MaterialProgressBar extends ProgressBar {
     public static final int PROGRESS_STYLE_CIRCULAR = 0;
     public static final int PROGRESS_STYLE_HORIZONTAL = 1;
 
+    // This field remains false inside super class constructor.
+    @SuppressWarnings("FieldCanBeLocal")
+    private boolean mSuperInitialized = true;
     private int mProgressStyle;
-
     private TintInfo mProgressTintInfo = new TintInfo();
 
     public MaterialProgressBar(Context context) {
@@ -146,6 +148,15 @@ private void init(AttributeSet attrs, int defStyleAttr, int defStyleRes) {
         setShowProgressBackground(showProgressBackground);
     }
 
+    @Override
+    public synchronized void setIndeterminate(boolean indeterminate) {
+        super.setIndeterminate(indeterminate);
+
+        if (mSuperInitialized && !(getCurrentDrawable() instanceof MaterialProgressDrawable)) {
+            Log.w(TAG, "Current drawable is not a MaterialProgressDrawable, you may want to set app:mpb_setBothDrawables");
+        }
+    }
+
     @Override
     protected void onAttachedToWindow() {
         super.onAttachedToWindow();

library/src/main/java/me/zhanghai/android/materialprogressbar/MaterialProgressDrawable.java

@@ -0,0 +1,8 @@
+/*
+ * Copyright (c) 2017 Zhang Hai <Dreaming.in.Code.ZH@Gmail.com>
+ * All Rights Reserved.
+ */
+
+package me.zhanghai.android.materialprogressbar;
+
+interface MaterialProgressDrawable {}