Use a real gaussian blur for the masked phone number

- Add BlurredTextSpan: draws the real glyphs through a BlurMaskFilter
  into a cached offscreen bitmap, so the blur works on both software and
  hardware-accelerated views
- formatOwnPhone() now returns this span in Blur mode instead of
  replacing digits with bullets
- SettingsActivity header builds the subtitle with a SpannableStringBuilder
  so the span is preserved

TMessagesProj/src/main/java/org/telegram/ui/SettingsActivity.java

@@ -529,7 +529,7 @@ public class SettingsActivity extends BaseFragment implements NotificationCenter
         avatarDrawable.setInfo(user);
         avatarView.setForUserOrChat(user, avatarDrawable);
         titleView.setText(UserObject.getUserName(user));
-        final StringBuilder sb = new StringBuilder();
+        final android.text.SpannableStringBuilder sb = new android.text.SpannableStringBuilder();
         if (user != null) {
             sb.append(tw.nekomimi.nekogram.NekoConfig.formatOwnPhone(PhoneFormat.getInstance().format("+" + user.phone)));
         }

TMessagesProj/src/main/java/tw/nekomimi/nekogram/NekoConfig.java

@@ -701,16 +701,12 @@ public class NekoConfig {
         if (hidePhoneNumber == PHONE_HIDE) {
             return org.telegram.messenger.LocaleController.getString(org.telegram.messenger.R.string.MobileHidden);
         }
-        StringBuilder sb = new StringBuilder(formatted.length());
-        for (int i = 0; i < formatted.length(); i++) {
-            char c = formatted.charAt(i);
-            if (Character.isDigit(c)) {
-                sb.append('•');
-            } else {
-                sb.append(c);
-            }
-        }
-        return sb.toString();
+        // PHONE_BLUR: render the real number, but genuinely blurred.
+        String text = formatted.toString();
+        android.text.SpannableString span = new android.text.SpannableString(text);
+        span.setSpan(new tw.nekomimi.nekogram.helpers.BlurredTextSpan(text), 0, text.length(),
+                android.text.Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
+        return span;
     }
 
     public static void setNameOrder(int order) {

TMessagesProj/src/main/java/tw/nekomimi/nekogram/helpers/BlurredTextSpan.java

@@ -0,0 +1,109 @@
+package tw.nekomimi.nekogram.helpers;
+
+import android.graphics.Bitmap;
+import android.graphics.BlurMaskFilter;
+import android.graphics.Canvas;
+import android.graphics.Paint;
+import android.text.style.ReplacementSpan;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
+import org.telegram.messenger.AndroidUtilities;
+
+/**
+ * Renders a piece of text genuinely blurred (Gaussian-style), instead of just
+ * masking the characters. The real glyphs are drawn into an offscreen software
+ * bitmap with a {@link BlurMaskFilter} applied and then blitted onto the target
+ * canvas, so it works the same on both software and hardware-accelerated views.
+ */
+public class BlurredTextSpan extends ReplacementSpan {
+
+    private final String text;
+    private final float blurRadius;
+
+    private Bitmap cache;
+    private int cacheWidth;
+    private int cacheHeight;
+    private float cacheTextSize;
+    private int cacheColor;
+    private float cacheBaseline;
+    private int cachePad;
+
+    public BlurredTextSpan(String text) {
+        this(text, AndroidUtilities.dp(3.5f));
+    }
+
+    public BlurredTextSpan(String text, float blurRadius) {
+        this.text = text == null ? "" : text;
+        this.blurRadius = Math.max(0.5f, blurRadius);
+    }
+
+    @Override
+    public int getSize(@NonNull Paint paint, CharSequence charSequence, int start, int end, @Nullable Paint.FontMetricsInt fm) {
+        if (fm != null) {
+            Paint.FontMetricsInt pfm = paint.getFontMetricsInt();
+            fm.ascent = pfm.ascent;
+            fm.descent = pfm.descent;
+            fm.top = pfm.top;
+            fm.bottom = pfm.bottom;
+            fm.leading = pfm.leading;
+        }
+        return (int) Math.ceil(paint.measureText(text));
+    }
+
+    @Override
+    public void draw(@NonNull Canvas canvas, CharSequence charSequence, int start, int end, float x, int top, int y, int bottom, @NonNull Paint paint) {
+        ensureCache(paint);
+        if (cache == null) {
+            return;
+        }
+        canvas.drawBitmap(cache, x - cachePad, y - cacheBaseline, null);
+    }
+
+    private void ensureCache(Paint paint) {
+        final float textSize = paint.getTextSize();
+        final int color = paint.getColor();
+        final int width = (int) Math.ceil(paint.measureText(text));
+        if (width <= 0) {
+            cache = null;
+            return;
+        }
+        // padding so the blur isn't clipped at the edges
+        final int pad = (int) Math.ceil(blurRadius * 2.5f);
+        Paint.FontMetricsInt fm = paint.getFontMetricsInt();
+        final int textHeight = fm.descent - fm.ascent;
+        final int w = width + pad * 2;
+        final int h = textHeight + pad * 2;
+
+        if (cache != null && cacheWidth == w && cacheHeight == h
+                && cacheTextSize == textSize && cacheColor == color) {
+            return;
+        }
+
+        if (cache != null) {
+            cache.recycle();
+        }
+        try {
+            cache = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
+        } catch (Throwable e) {
+            cache = null;
+            return;
+        }
+        cacheWidth = w;
+        cacheHeight = h;
+        cacheTextSize = textSize;
+        cacheColor = color;
+        cachePad = pad;
+        // baseline offset inside the cache bitmap, relative to the text top
+        cacheBaseline = pad - fm.ascent;
+
+        Canvas c = new Canvas(cache);
+        Paint p = new Paint(Paint.ANTI_ALIAS_FLAG);
+        p.setTextSize(textSize);
+        p.setColor(color);
+        p.setTypeface(paint.getTypeface());
+        p.setMaskFilter(new BlurMaskFilter(blurRadius, BlurMaskFilter.Blur.NORMAL));
+        c.drawText(text, pad, cacheBaseline, p);
+    }
+}