Added chips

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

@@ -0,0 +1,38 @@
+package eu.faircode.email;
+
+import android.graphics.Canvas;
+import android.graphics.Paint;
+import android.graphics.RectF;
+import android.text.style.ReplacementSpan;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
+public class ChipSpan extends ReplacementSpan {
+    private int bg;
+    private int fg;
+    private int radius;
+
+    public ChipSpan(int bg, int fg, int radius) {
+        super();
+        this.bg = bg;
+        this.fg = fg;
+        this.radius = radius;
+    }
+
+    @Override
+    public int getSize(@NonNull Paint paint, CharSequence text, int start, int end, @Nullable Paint.FontMetricsInt fm) {
+        return Math.round(paint.measureText(text, start, end) + 2 * radius);
+    }
+
+    @Override
+    public void draw(@NonNull Canvas canvas, CharSequence text, int start, int end, float x, int top, int y, int bottom, @NonNull Paint paint) {
+        RectF rect = new RectF(x, top, x + paint.measureText(text, start, end) + 2 * radius, bottom);
+        paint.setColor(bg);
+        canvas.drawRoundRect(rect, radius, radius, paint);
+
+        paint.setStyle(Paint.Style.FILL);
+        paint.setColor(fg);
+        canvas.drawText(text, start, end, x + radius, y, paint);
+    }
+}

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

@@ -293,6 +293,42 @@ public class FragmentCompose extends FragmentBase {
             }
         });
 
+        final int chipBackground = Helper.resolveColor(getContext(), R.attr.colorPrimary);
+        final int chipForeground = Color.WHITE;
+        final int chipRadius = Helper.dp2pixels(getContext(), 6);
+
+        TextWatcher chip = new TextWatcher() {
+            @Override
+            public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
+            }
+
+            @Override
+            public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
+            }
+
+            @Override
+            public void afterTextChanged(Editable editable) {
+                for (Object span : editable.getSpans(0, editable.length(), ChipSpan.class))
+                    editable.removeSpan(span);
+
+                int start = 0;
+                for (int i = 0; i < editable.length(); i++)
+                    if (editable.charAt(i) == ',') {
+                        if (i > start) {
+                            if (editable.charAt(start) == ' ')
+                                start++;
+                            editable.setSpan(new ChipSpan(chipBackground, chipForeground, chipRadius),
+                                    start, i, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
+                        }
+                        start = i + 1;
+                    }
+            }
+        };
+
+        etTo.addTextChangedListener(chip);
+        etCc.addTextChangedListener(chip);
+        etBcc.addTextChangedListener(chip);
+
         View.OnClickListener onPick = new View.OnClickListener() {
             @Override
             public void onClick(View view) {