修复文字渐变色在某些字母（ypgj）底部显示不正常的问题

Author: getActivity

app/src/main/res/layout/activity_main.xml

@@ -384,7 +384,7 @@
                 android:layout_margin="10dp"
                 android:gravity="center"
                 android:padding="10dp"
-                android:text="文本垂直渐变效果"
+                android:text="文本垂直渐变效果ypgj"
                 android:textSize="18sp"
                 app:shape_textEndColor="#ED58FF"
                 app:shape_textGradientOrientation="vertical"

library/src/main/java/com/hjq/shape/span/LinearGradientFontSpan.java

@@ -3,6 +3,7 @@
 import android.graphics.Canvas;
 import android.graphics.LinearGradient;
 import android.graphics.Paint;
+import android.graphics.Paint.FontMetricsInt;
 import android.graphics.Shader;
 import android.support.annotation.NonNull;
 import android.text.SpannableStringBuilder;
@@ -58,8 +59,9 @@ public void onDraw(@NonNull Canvas canvas, @NonNull Paint paint, CharSequence te
                                 int start, int end, float x, int top, int y, int bottom) {
         LinearGradient linearGradient;
         if (mTextGradientOrientation == GRADIENT_ORIENTATION_VERTICAL) {
-            linearGradient = new LinearGradient(0, 0, 0, paint.descent() - paint.ascent(),
-                    mTextGradientColor, mTextGradientPositions, Shader.TileMode.REPEAT);
+            FontMetricsInt fontMetrics = paint.getFontMetricsInt();
+            linearGradient = new LinearGradient(0, 0, 0, fontMetrics.bottom - fontMetrics.top,
+                mTextGradientColor, mTextGradientPositions, Shader.TileMode.MIRROR);
         } else {
             linearGradient = new LinearGradient(x, 0, x + textWidth, 0,
                     mTextGradientColor, mTextGradientPositions, Shader.TileMode.REPEAT);