Add native resolution width/height specifier

nomadnet/ui/textui/images/_selftest.py

@@ -255,7 +255,7 @@ def test_webp_conversion():
         with os.fdopen(fd, "wb") as f:
             f.write(fixture)
         d = ImageData(webp_path)
-        check(not d.ok and "converted image too large" in d.error,
+        check(not d.ok and "Converted image too large" in d.error,
               "converted payload capped at %d MiB"
               % (MAX_CONVERTED_PAYLOAD_BYTES // (1024 * 1024)))
         os.unlink(webp_path)
@@ -414,6 +414,43 @@ def test_widget_layout(image_path):
         check((c, r) == (27, 10), "height-only after reset -> (27, 10), got (%d, %d)" % (c, r))
         w.close()
 
+        # native resolution specification ("n"): display at the image's own
+        # pixel size, quantized to the terminal cell grid. Cell = (1, 2),
+        # small fixture 64x32 -> native 64 cols, 16 rows.
+        from nomadnet.ui.textui.images import _webp
+        small_png = _webp._encode_png_rgba(bytes(64 * 32 * 4), 64, 32)
+        fd, small_path = tempfile.mkstemp(suffix=".png")
+        with os.fdopen(fd, "wb") as f:
+            f.write(small_png)
+        try:
+            wn = ImageWidget(small_path, width="n")
+            wn.render((80,))  # sets _ti_cols/_ti_rows
+            check((wn._ti_cols, wn._ti_rows) == (64, 16),
+                  "width='n' displays native size (64, 16), got (%d, %d)"
+                  % (wn._ti_cols, wn._ti_rows))
+            wn.close()
+            hn = ImageWidget(small_path, height="n")
+            hn.render((80,))
+            check((hn._ti_cols, hn._ti_rows) == (64, 16),
+                  "height='n' displays native size (64, 16), got (%d, %d)"
+                  % (hn._ti_cols, hn._ti_rows))
+            hn.close()
+            bn = ImageWidget(small_path, width="n", height="n")
+            bn.render((80,))
+            check((bn._ti_cols, bn._ti_rows) == (64, 16),
+                  "width='n' height='n' displays native size (64, 16), got (%d, %d)"
+                  % (bn._ti_cols, bn._ti_rows))
+            bn.close()
+            big = ImageWidget(image_path, width="n")  # 1280x960, overflows
+            c, r = big._display_size(80)
+            check((c, r) == (80, 30),
+                  "native of a large image clamps to available width (80, 30), got (%d, %d)" % (c, r))
+            big.close()
+            check(raises(lambda: ImageWidget(image_path, width="x"), ValueError),
+                  "width='x' raises ValueError")
+        finally:
+            os.unlink(small_path)
+
         # alignment: placement column of a narrowed image inside its canvas
         w = ImageWidget(image_path, width=40)  # default center
         w.render((80,))  # sets _ti_cols/_ti_rows

nomadnet/ui/textui/images/widget.py

@@ -33,6 +33,7 @@ def _check_align(value):
 
 
 def _check_size_spec(value, name):
+    # None = auto, int = absolute cells/rows, "NN%" = percent, "n" = native resolution
     if value is None: return None
     
     if isinstance(value, int):
@@ -40,9 +41,10 @@ def _check_size_spec(value, name):
         return value
     
     if isinstance(value, str):
+        if value.lower() == "n": return "n"
         match = _SIZE_SPEC_RE.fullmatch(value)
         if not match or float(match.group(1)) <= 0:
-            raise ValueError("invalid %s specification %r (expected a positive integer or a percent string like '50%%')" % (name, value))
+            raise ValueError("invalid %s specification %r (expected a positive integer, a percent string like '50%%' or 'n' for native resolution)" % (name, value))
         return value
     
     raise TypeError("invalid type for %s (got %s)" % (name, type(value).__name__))
@@ -140,8 +142,8 @@ class ImageWidget(urwid.Widget):
     width = property(
         lambda self: self._ti_width,
         doc="""Display width specification: None (full width), a positive
-        int (columns) or a percent string ("NN%") of the available layout
-        width.""",
+        int (columns), a percent string ("NN%") of the available layout
+        width, or "n" for native resolution.""",
     )
 
     @width.setter
@@ -152,8 +154,8 @@ class ImageWidget(urwid.Widget):
     height = property(
         lambda self: self._ti_height,
         doc="""Display height specification: None (derived, aspect
-        preserving), a positive int (rows) or a percent string ("NN%") of
-        the visible page height.""",
+        preserving), a positive int (rows), a percent string ("NN%") of
+        the visible page height, or "n" for native resolution.""",
     )
 
     @height.setter
@@ -185,11 +187,13 @@ class ImageWidget(urwid.Widget):
         def _raw_width():
             if w_spec is None: return float(maxcol)
             if isinstance(w_spec, int): return float(w_spec)
+            if w_spec == "n": return iw / cell_w
             return maxcol * _pct(w_spec)
 
         def _raw_height():
             if h_spec is None: return None
             if isinstance(h_spec, int): return float(h_spec)
+            if h_spec == "n": return ih / cell_h
             columns, lines = _termlib.get_terminal_size()
             page = max(1, lines - UI_MARGIN)
             return page * _pct(h_spec)