Added support for square bullets

app/src/main/java/eu/faircode/email/BulletSpanEx.java

@@ -23,6 +23,7 @@ import android.graphics.Canvas;
 import android.graphics.Paint;
 import android.os.Build;
 import android.text.Layout;
+import android.text.Spanned;
 import android.text.style.BulletSpan;
 
 import androidx.annotation.NonNull;
@@ -77,6 +78,53 @@ public class BulletSpanEx extends BulletSpan {
     public void drawLeadingMargin(@NonNull Canvas canvas, @NonNull Paint paint, int x, int dir, int top, int baseline, int bottom, @NonNull CharSequence text, int start, int end, boolean first, @Nullable Layout layout) {
         if ("none".equals(ltype))
             return;
-        super.drawLeadingMargin(canvas, paint, x + indentWidth * (level + 1) * dir, dir, top, baseline, bottom, text, start, end, first, layout);
+
+        boolean mWantColor = false;
+        int mColor = 0; // STANDARD_COLOR
+        int mBulletRadius = 4; // STANDARD_BULLET_RADIUS
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
+            mWantColor = true;
+            mColor = getColor();
+            mBulletRadius = getBulletRadius();
+        }
+
+        if (((Spanned) text).getSpanStart(this) == start) {
+            Paint.Style style = paint.getStyle();
+            int oldcolor = 0;
+
+            if (mWantColor) {
+                oldcolor = paint.getColor();
+                paint.setColor(mColor);
+            }
+
+            paint.setStyle(Paint.Style.FILL);
+
+            if (layout != null) {
+                // "bottom" position might include extra space as a result of line spacing
+                // configuration. Subtract extra space in order to show bullet in the vertical
+                // center of characters.
+                final int line = layout.getLineForOffset(start);
+                //bottom = bottom - layout.getLineExtra(line);
+            }
+
+            final float yPosition = (top + bottom) / 2f;
+            final float xPosition = x + dir * mBulletRadius;
+
+            if ("square".equals(ltype))
+                canvas.drawRect(
+                        xPosition - mBulletRadius,
+                        yPosition - mBulletRadius,
+                        xPosition + mBulletRadius,
+                        yPosition + mBulletRadius,
+                        paint);
+            else
+                canvas.drawCircle(xPosition, yPosition, mBulletRadius, paint);
+
+            if (mWantColor) {
+                paint.setColor(oldcolor);
+            }
+
+            paint.setStyle(style);
+        }
     }
 }