Layout improvement, refactoring

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

@@ -0,0 +1,37 @@
+package eu.faircode.email;
+
+import android.graphics.Canvas;
+import android.graphics.Paint;
+import android.text.Layout;
+import android.text.style.QuoteSpan;
+
+import androidx.annotation.NonNull;
+
+public class StyledQuoteSpan extends QuoteSpan {
+    StyledQuoteSpan(int color) {
+        super(color);
+    }
+
+    @Override
+    public int getLeadingMargin(boolean first) {
+        return 6 /* stripeWidth */ + 12 /* gapWidth */;
+    }
+
+    @Override
+    public void drawLeadingMargin(
+            @NonNull Canvas c, @NonNull Paint p,
+            int x, int dir, int top, int baseline, int bottom,
+            @NonNull CharSequence text, int start, int end, boolean first,
+            @NonNull Layout layout) {
+        Paint.Style style = p.getStyle();
+        int color = p.getColor();
+
+        p.setStyle(Paint.Style.FILL);
+        p.setColor(getColor());
+
+        c.drawRect(x, top, x + dir * 6 /* stripeWidth */, bottom, p);
+
+        p.setStyle(style);
+        p.setColor(color);
+    }
+}