gtk: Create a MessageView

The message view will be used to display either stdout or stderr
messages to the user. It has built-in 'diff' detection, and adds nice
colors to the diff output if we are asked to display one.

Signed-off-by: Anna Schumaker <anna@nowheycreamery.com>

tests/gtk/test_view.py

@@ -257,6 +257,101 @@ class TestTestCaseView(unittest.TestCase):
                                          "stdout", "stderr")
 
 
+class TestMessageView(unittest.TestCase):
+    """Test the MessageView."""
+
+    def setUp(self):
+        """Set up common variables."""
+        self.view = xfstestsdb.gtk.view.MessageView("title")
+
+    def test_init(self):
+        """Check that the MessageView was set up correctly."""
+        self.assertIsInstance(self.view, Gtk.Box)
+        self.assertEqual(self.view.props.orientation, Gtk.Orientation.VERTICAL)
+        self.assertTrue(self.view.has_css_class("view"))
+
+    def test_detect_diff(self):
+        """Check detecting if input test looks like a diff."""
+        self.assertFalse(self.view.detect_diff("not a diff"))
+        lines = ["+++ /some/file"]
+        self.assertFalse(self.view.detect_diff("\n".join(lines)))
+        lines.append("--- /some/other/file")
+        self.assertFalse(self.view.detect_diff("\n".join(lines)))
+        lines.append("@@ 12,34,5 @@")
+        self.assertFalse(self.view.detect_diff("\n".join(lines)))
+        lines.append(" some context line")
+        self.assertTrue(self.view.detect_diff("\n".join(lines)))
+        lines[-1] = "+an added line"
+        self.assertTrue(self.view.detect_diff("\n".join(lines)))
+        lines[-1] = "-a removed line"
+        self.assertTrue(self.view.detect_diff("\n".join(lines)))
+
+    def test_markup_diff(self):
+        """Check colorizing lines with diff colors."""
+        self.assertEqual(self.view.markup_diff("abcde"), "abcde")
+        self.assertEqual(self.view.markup_diff("+++ /some/file"),
+                         "<span color='#26a269'>+++ /some/file</span>")
+        self.assertEqual(self.view.markup_diff("--- /some/other/file"),
+                         "<span color='#c01c28'>--- /some/other/file</span>")
+        self.assertEqual(self.view.markup_diff("@@ 12,34,5 @@"),
+                         "<span color='#1c71d8'>@@ 12,34,5 @@</span>")
+        self.assertEqual(self.view.markup_diff(" a context line"),
+                         "<span color='#77767b'> a context line</span>")
+        self.assertEqual(self.view.markup_diff("+an added line"),
+                         "<span color='#26a269'>+an added line</span>")
+        self.assertEqual(self.view.markup_diff("-a removed line"),
+                         "<span color='#c01c28'>-a removed line</span>")
+
+    def test_title(self):
+        """Test the title widgets."""
+        self.assertIsInstance(self.view._label, Gtk.Label)
+        self.assertIsInstance(self.view._label.get_next_sibling(),
+                              Gtk.Separator)
+        self.assertEqual(self.view.get_first_child(), self.view._label)
+
+        self.assertEqual(self.view.title, "title")
+        self.assertEqual(self.view._label.props.label, "title")
+        self.assertEqual(self.view._label.props.margin_top, 6)
+        self.assertTrue(self.view._label.has_css_class("large-title"))
+
+    def test_text(self):
+        """Test the text property."""
+        win = self.view.get_last_child()
+        self.assertIsInstance(win, Gtk.ScrolledWindow)
+        self.assertIsInstance(self.view._textview, Gtk.TextView)
+        self.assertEqual(win.props.child, self.view._textview)
+        self.assertTrue(win.props.vexpand)
+
+        self.assertFalse(self.view._textview.props.editable)
+        self.assertTrue(self.view._textview.props.monospace)
+
+        buffer = self.view._textview.get_buffer()
+        self.assertEqual(self.view.text, "")
+        with unittest.mock.patch.object(buffer, "set_text",
+                                        wraps=buffer.set_text) as mock_set:
+            self.view.text = "text"
+            self.assertEqual(buffer.get_text(buffer.get_start_iter(),
+                                             buffer.get_end_iter(), True),
+                             "text")
+            mock_set.assert_called_with("text")
+            self.assertEqual(self.view.text, "text")
+
+    def test_text_diff(self):
+        """Test setting the text property to a diff string."""
+        buffer = self.view._textview.get_buffer()
+        diff = ["+++ /some/file", "--- /some/other/file", "@@ 12,34,5 @@",
+                " context line", "-removed line", "+added line"]
+
+        with unittest.mock.patch.object(buffer, "set_text",
+                                        wraps=buffer.set_text) as mock_set:
+            self.view.text = "\n".join(diff)
+            mock_set.assert_not_called()
+            self.assertEqual(self.view.text, "\n".join(diff))
+
+            self.view.text = "\n".join(diff)
+            self.assertEqual(self.view.text, "\n".join(diff))
+
+
 class TestSummaryView(unittest.TestCase):
     """Tests the SummaryView."""
 

xfstestsdb/gtk/view.py

@@ -1,5 +1,6 @@
 # Copyright 2023 (c) Anna Schumaker.
 """A view widget used to display our TestCaseModel."""
+import re
 from gi.repository import GObject
 from gi.repository import Gio
 from gi.repository import Gtk
@@ -164,6 +165,72 @@ class TestCaseView(XunitView):
         """Signal that the user wants to inspect stdout and stderr messages."""
 
 
+class MessageView(Gtk.Box):
+    """A view for displaying a multiline test result message."""
+
+    title = GObject.Property(type=str)
+
+    def __init__(self, title: str):
+        """Initialize a MessageView."""
+        super().__init__(title=title, orientation=Gtk.Orientation.VERTICAL)
+        self._label = Gtk.Label(label=self.title, margin_top=6)
+        self._textview = Gtk.TextView(monospace=True, editable=False)
+
+        self.append(self._label)
+        self.append(Gtk.Separator())
+        self.append(Gtk.ScrolledWindow(child=self._textview, vexpand=True))
+
+        self._label.add_css_class("large-title")
+        self.add_css_class("view")
+
+    def detect_diff(self, text: str) -> bool:
+        """Detect if the given text looks like a diff."""
+        in_file = out_file = counts = changed = False
+
+        for line in text.split("\n"):
+            if re.match(r"^\+\+\+", line):
+                in_file = True
+            elif re.match(r"^---", line):
+                out_file = True
+            elif re.match(r"^@@(.*?)@@", line):
+                counts = True
+            elif re.match(r"^[\+| |-](.*?)", line):
+                changed = True
+
+        return in_file and out_file and counts and changed
+
+    def markup_diff(self, text: str) -> str:
+        """Add Pango markup to the input string."""
+        if re.match(r"^\++(.*?)", text):
+            return f"<span color='#26a269'>{text}</span>"
+        elif re.match(r"^-+(.*?)", text):
+            return f"<span color='#c01c28'>{text}</span>"
+        elif re.match(r"^@@(.*?)@@", text):
+            return f"<span color='#1c71d8'>{text}</span>"
+        elif re.match(r"^ (.*?)", text):
+            return f"<span color='#77767b'>{text}</span>"
+        return text
+
+    @GObject.Property(type=str)
+    def text(self) -> str:
+        """Get the text displayed in the view."""
+        buffer = self._textview.props.buffer
+        return buffer.get_text(buffer.get_start_iter(),
+                               buffer.get_end_iter(), True)
+
+    @text.setter
+    def text(self, new_text: str) -> None:
+        buffer = self._textview.props.buffer
+        if self.detect_diff(new_text):
+            buffer.delete(buffer.get_start_iter(), buffer.get_end_iter())
+            for i, line in enumerate(new_text.split("\n")):
+                text = self.markup_diff(line)
+                text = f"\n{text}" if i > 0 else text
+                buffer.insert_markup(buffer.get_end_iter(), text, len(text))
+        else:
+            buffer.set_text(new_text)
+
+
 class SummaryView(XunitView):
     """Displays our SummaryList model to the user."""