Don't check for MeasureSpec.EXACTLY width because RelativeLayout may …

…call onMeasure with intermediate EXACTLY spec.

README.md

@@ -34,6 +34,8 @@ implementation "com.android.support:appcompat-v7:x.x.x"
     android:layout_width="wrap_content"
     android:layout_height="wrap_content" />
 ```
+There is no possibility to set fixed indicator width (because it's width is based on ```spi_visibleDotCount```).
+
 3. Attach indicator to ViewPager:
 ```java
 ViewPager pager = findViewById(R.id.pager);

library/src/main/java/ru/tinkoff/scrollingpagerindicator/ScrollingPagerIndicator.java

@@ -303,13 +303,11 @@ public void setCurrentPosition(int position) {
     @Override
     protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
         // Width
-        int widthMode = MeasureSpec.getMode(widthMeasureSpec);
-        if (widthMode == MeasureSpec.EXACTLY) {
-            throw new IllegalStateException("Fixed width is not supported");
-        }
         int measuredWidth;
+        // We ignore widthMeasureSpec because width is based on visibleDotCount
         if (isInEditMode()) {
-            measuredWidth = MeasureSpec.getSize(widthMeasureSpec);
+            // Maximum width with all dots visible
+            measuredWidth = (visibleDotCount - 1) * spaceBetweenDotCenters + dotSelectedSize;
         } else {
             measuredWidth = dotCount >= visibleDotCount
                     ? (int) visibleFrameWidth