Elide source designation at lower window widths

securedrop_client/gui/__init__.py

@@ -184,8 +184,8 @@ def get_elided_text(self, full_text: str) -> str:
             full_text = full_text.split("\n", 1)[0]
 
         fm = self.fontMetrics()
-        filename_width = fm.horizontalAdvance(full_text)
-        if filename_width > self.max_length:
+        px_width = fm.horizontalAdvance(full_text)
+        if px_width > self.max_length:
             elided_text = ""
             for c in full_text:
                 if fm.horizontalAdvance(elided_text) > self.max_length:

securedrop_client/gui/widgets.py

@@ -3133,8 +3133,25 @@ def setText(self, text):
             self.placeholder.hide()
         super(ReplyTextEdit, self).setPlainText(text)
 
+    def resizeEvent(self, event):
+        # Adjust available source label width to elide text when necessary
+        self.placeholder.update_label_width(event.size().width())
+        super().resizeEvent(event)
+
 
 class ReplyTextEditPlaceholder(QWidget):
+
+    # These values are used to determine the width that can be taken up by
+    # the source designation as the widget is initialized or the window is
+    # resized.
+    INITIAL_MAX_WIDTH = 150
+    RESERVED_WIDTH = 250
+
+    # We allocate a fixed with to the source designation because its text is
+    # dynamically resized, which otherwise causes Qt's layout engine to
+    # incorrectly reposition it
+    FIXED_LABEL_WIDTH = 800
+
     def __init__(self, source_name):
         super().__init__()
 
@@ -3147,14 +3164,18 @@ def __init__(self, source_name):
         # Signed in
         compose_a_reply_to = QLabel(_("Compose a reply to "))
         compose_a_reply_to.setObjectName("ReplyTextEditPlaceholder_text")
-        source_name = SecureQLabel(source_name, wordwrap=False)
-        source_name.setObjectName("ReplyTextEditPlaceholder_bold_blue")
+        self.source_name = source_name
+        self.source_name_label = SecureQLabel(
+            source_name, wordwrap=False, max_length=self.INITIAL_MAX_WIDTH
+        )
+        self.source_name_label.setObjectName("ReplyTextEditPlaceholder_bold_blue")
+        self.source_name_label.setFixedWidth(self.FIXED_LABEL_WIDTH)
         self.signed_in = QWidget()
         signed_in_layout = QHBoxLayout()
         signed_in_layout.setSpacing(0)
         self.signed_in.setLayout(signed_in_layout)
         signed_in_layout.addWidget(compose_a_reply_to)
-        signed_in_layout.addWidget(source_name)
+        signed_in_layout.addWidget(self.source_name_label)
         self.signed_in.hide()
 
         # Awaiting key
@@ -3203,6 +3224,13 @@ def show_signed_out(self):
         self.signed_in.hide()
         self.signed_out.show()
 
+    def update_label_width(self, width):
+        if width > self.RESERVED_WIDTH:
+            # Ensure source designations are elided with "..." if needed per
+            # current container size
+            self.source_name_label.max_length = width - self.RESERVED_WIDTH
+            self.source_name_label.setText(self.source_name)
+
 
 class DeleteSourceAction(QAction):
     """Use this action to delete the source record."""

tests/gui/test_widgets.py

@@ -37,6 +37,7 @@
     PrintDialog,
     ReplyBoxWidget,
     ReplyTextEdit,
+    ReplyTextEditPlaceholder,
     ReplyWidget,
     SecureQLabel,
     SourceConversationWrapper,
@@ -4362,6 +4363,37 @@ def test_ReplyBox_set_logged_in_no_public_key(mocker):
     assert rb.text_edit.isEnabled() is False
 
 
+def test_ReplyBox_resize_adjusts_label_width(mocker):
+    """
+    If the reply widget is resized, the source designation's maximum width is
+    updated, and text is elided if necessary.
+    """
+    source = factory.Source()
+    source.journalist_designation = "omniscient hippopotamus"
+    controller = mocker.MagicMock()
+    rb = ReplyBoxWidget(source, controller)
+    rb.set_logged_in()
+
+    # The widget must be displayed for the resize event to be triggered.
+    rb.show()
+
+    # We wrap the update_label_width method so we can verify that it has been
+    # called while preserving its behavior.
+    with patch.object(
+        ReplyTextEditPlaceholder,
+        "update_label_width",
+        wraps=rb.text_edit.placeholder.update_label_width,
+    ) as wrapped_update:
+        rb.resize(1000, rb.height())
+        wrapped_update.assert_called_with(rb.text_edit.width() - 2)
+        assert rb.text_edit.placeholder.source_name_label.elided is False
+        rb.resize(500, rb.height())
+        wrapped_update.assert_called_with(rb.text_edit.width() - 2)
+        assert rb.text_edit.placeholder.source_name_label.elided is True
+
+    rb.hide()
+
+
 def test_update_conversation_maintains_old_items(mocker, session):
     """
     Calling update_conversation maintains old item state / position if there's