[TopAppBar] Fix expanded title margin not applied

In the original logic we compares interpolated text size to decide if the available width should be the collapsed one or the expanded one. This logic wouldn't work if the collapsed text size and the expanded text size are the same. Refactors the logic to make the decision by interpolating fraction directly.

Resolves #2459

PiperOrigin-RevId: 410901171

Author: drchen

lib/java/com/google/android/material/internal/CollapsingTextHelper.java

@@ -599,21 +599,20 @@ private void calculateOffsets(final float fraction) {
         currentDrawX = expandedDrawX;
         currentDrawY = expandedDrawY;
 
-        setInterpolatedTextSize(expandedTextSize);
+        setInterpolatedTextSize(/* fraction= */ 0);
       } else {
         textBlendFraction = 1F;
         currentDrawX = collapsedDrawX;
         currentDrawY = collapsedDrawY - max(0, currentOffsetY);
 
-        setInterpolatedTextSize(collapsedTextSize);
+        setInterpolatedTextSize(/* fraction= */ 1);
       }
     } else {
       textBlendFraction = fraction;
       currentDrawX = lerp(expandedDrawX, collapsedDrawX, fraction, positionInterpolator);
       currentDrawY = lerp(expandedDrawY, collapsedDrawY, fraction, positionInterpolator);
 
-      setInterpolatedTextSize(
-          lerp(expandedTextSize, collapsedTextSize, fraction, textSizeInterpolator));
+      setInterpolatedTextSize(fraction);
     }
 
     setCollapsedTextBlend(
@@ -703,10 +702,8 @@ private int getCurrentColor(@Nullable ColorStateList colorStateList) {
   }
 
   private void calculateBaseOffsets(boolean forceRecalculate) {
-    final float currentTextSize = this.currentTextSize;
-
     // We then calculate the collapsed text size, using the same logic
-    calculateUsingTextSize(collapsedTextSize, forceRecalculate);
+    calculateUsingTextSize(/* fraction= */ 1, forceRecalculate);
     if (textToDraw != null && textLayout != null) {
       textToDrawCollapsed =
           TextUtils.ellipsize(textToDraw, textPaint, textLayout.getWidth(), TruncateAt.END);
@@ -748,7 +745,7 @@ private void calculateBaseOffsets(boolean forceRecalculate) {
         break;
     }
 
-    calculateUsingTextSize(expandedTextSize, forceRecalculate);
+    calculateUsingTextSize(/* fraction= */ 0, forceRecalculate);
     float expandedTextHeight = textLayout != null ? textLayout.getHeight() : 0;
     float expandedTextWidth = 0;
     if (textLayout != null && maxLines > 1) {
@@ -792,7 +789,7 @@ private void calculateBaseOffsets(boolean forceRecalculate) {
     // The bounds have changed so we need to clear the texture
     clearTexture();
     // Now reset the text size back to the original
-    setInterpolatedTextSize(currentTextSize);
+    setInterpolatedTextSize(expandedFraction);
   }
 
   private float measureTextWidth(TextPaint textPaint, CharSequence textToDraw) {
@@ -923,8 +920,8 @@ private boolean isTextDirectionHeuristicsIsRtl(@NonNull CharSequence text, boole
         .isRtl(text, 0, text.length());
   }
 
-  private void setInterpolatedTextSize(float textSize) {
-    calculateUsingTextSize(textSize);
+  private void setInterpolatedTextSize(float fraction) {
+    calculateUsingTextSize(fraction);
 
     // Use our texture if the scale isn't 1.0
     useTexture = USE_SCALING_TEXTURE && scale != 1f;
@@ -937,12 +934,12 @@ private void setInterpolatedTextSize(float textSize) {
     ViewCompat.postInvalidateOnAnimation(view);
   }
 
-  private void calculateUsingTextSize(final float textSize) {
-    calculateUsingTextSize(textSize, /* forceRecalculate= */ false);
+  private void calculateUsingTextSize(final float fraction) {
+    calculateUsingTextSize(fraction, /* forceRecalculate= */ false);
   }
 
   @SuppressWarnings("ReferenceEquality") // Matches the Typeface comparison in TextView
-  private void calculateUsingTextSize(final float textSize, boolean forceRecalculate) {
+  private void calculateUsingTextSize(final float fraction, boolean forceRecalculate) {
     if (text == null) {
       return;
     }
@@ -955,7 +952,7 @@ private void calculateUsingTextSize(final float textSize, boolean forceRecalcula
     float newLetterSpacing;
     boolean updateDrawText = false;
 
-    if (isClose(textSize, collapsedTextSize)) {
+    if (isClose(fraction, /* targetValue= */ 1)) {
       newTextSize = collapsedTextSize;
       newLetterSpacing = collapsedLetterSpacing;
       scale = 1f;
@@ -971,12 +968,14 @@ private void calculateUsingTextSize(final float textSize, boolean forceRecalcula
         currentTypeface = expandedTypeface;
         updateDrawText = true;
       }
-      if (isClose(textSize, expandedTextSize)) {
+      if (isClose(fraction, /* targetValue= */ 0)) {
         // If we're close to the expanded text size, snap to it and use a scale of 1
         scale = 1f;
       } else {
         // Else, we'll scale down from the expanded text size
-        scale = textSize / expandedTextSize;
+        scale =
+            lerp(expandedTextSize, collapsedTextSize, fraction, textSizeInterpolator)
+                / expandedTextSize;
       }
 
       float textSizeRatio = collapsedTextSize / expandedTextSize;
@@ -1185,10 +1184,10 @@ public int getHyphenationFrequency() {
 
   /**
    * Returns true if {@code value} is 'close' to it's closest decimal value. Close is currently
-   * defined as it's difference being < 0.001.
+   * defined as it's difference being < 0.00001.
    */
   private static boolean isClose(float value, float targetValue) {
-    return Math.abs(value - targetValue) < 0.001f;
+    return Math.abs(value - targetValue) < 0.00001f;
   }
 
   public ColorStateList getExpandedTextColor() {