1 files changed, 79 insertions, 0 deletions
diff --git a/java/org/gnu/emacs/EmacsDrawLine.java b/java/org/gnu/emacs/EmacsDrawLine.java
new file mode 100644
index 00000000000..d367ccff9c4
--- /dev/null
+++ b/java/org/gnu/emacs/EmacsDrawLine.java
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+/* Communication module for Android terminals.  -*- c-file-style: "GNU" -*-
+
+Copyright (C) 2023 Free Software Foundation, Inc.
+
+This file is part of GNU Emacs.
+
+GNU Emacs is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or (at
+your option) any later version.
+
+GNU Emacs is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
+
+package org.gnu.emacs;
+
+import android.graphics.Canvas;
+import android.graphics.Paint;
+import android.graphics.Rect;
+
+public final class EmacsDrawLine
+{
+  public static void
+  perform (EmacsDrawable drawable, EmacsGC gc,
+	   int x, int y, int x2, int y2)
+  {
+    Rect rect;
+    Canvas canvas;
+    Paint paint;
+    int x0, x1, y0, y1;
+
+    /* TODO implement stippling.  */
+    if (gc.fill_style == EmacsGC.GC_FILL_OPAQUE_STIPPLED)
+      return;
+
+    /* Calculate the leftmost and rightmost points.  */
+
+    x0 = Math.min (x, x2 + 1);
+    x1 = Math.max (x, x2 + 1);
+    y0 = Math.min (y, y2 + 1);
+    y1 = Math.max (y, y2 + 1);
+
+    /* And the clip rectangle.  */
+
+    paint = gc.gcPaint;
+    rect = new Rect (x0, y0, x1, y1);
+    canvas = drawable.lockCanvas (gc);
+
+    if (canvas == null)
+      return;
+
+    paint.setStyle (Paint.Style.FILL);
+
+    /* Since drawLine has PostScript style behavior, adjust the
+       coordinates appropriately.
+
+       The left most pixel of a straight line is always partially
+       filled.  Patch it in manually.  */
+
+    if (gc.clip_mask == null)
+      {
+	canvas.drawLine ((float) x + 0.5f, (float) y + 0.5f,
+			 (float) x2 + 0.5f, (float) y2 + 0.5f,
+			 paint);
+
+	if (x2 > x)
+	  canvas.drawRect (new Rect (x, y, x + 1, y + 1), paint);
+      }
+
+    /* DrawLine with clip mask not implemented; it is not used by
+       Emacs.  */
+    drawable.damageRect (rect);
+  }
+}