add bal/gui

bal/gui/qt/window_utils.py

@@ -0,0 +1,119 @@
+"""
+bal.gui.qt.window_utils
+=======================
+
+Centralized window/dialog presentation helpers.
+
+The original plugin opened dialogs inconsistently: some with ``exec()``
+(modal, stays on top) and some with ``show()`` (modeless, can fall *behind*
+the main Electrum window). It also relied on a per-instance ``self.parent``
+attribute that shadows :meth:`QWidget.parent`, and it never gave non-modal
+dialogs focus, so they could disappear behind Electrum.
+
+To fix this *without changing the business logic*, all the "how is this window
+shown / focused / parented" concerns are collected here. The rest of the GUI
+code just calls these helpers, so the behaviour is consistent and easy to
+audit.
+
+None of these helpers change *what* a dialog does — only its parenting,
+modality and z-order/focus.
+"""
+
+from PyQt6.QtCore import Qt
+from PyQt6.QtWidgets import QWidget
+
+
+def top_level_of(widget):
+    """Return the proper top-level window to use as a dialog parent.
+
+    Electrum widgets expose ``top_level_window()``; when available we use it so
+    the dialog is anchored to the real top-level Electrum window (and therefore
+    stays in front of it). Falls back to the widget's own ``window()`` or the
+    widget itself.
+    """
+    if widget is None:
+        return None
+    # Electrum's MessageBoxMixin / ElectrumWindow provide top_level_window().
+    tlw = getattr(widget, "top_level_window", None)
+    if callable(tlw):
+        try:
+            return tlw()
+        except Exception:
+            pass
+    # Plain QWidget: window() returns the top-level container.
+    if isinstance(widget, QWidget):
+        try:
+            return widget.window()
+        except Exception:
+            pass
+    return widget
+
+
+def bring_to_front(dialog):
+    """Make a *visible* dialog actually appear in front and take focus.
+
+    ``raise_()`` alone is not enough on some window managers (notably Windows):
+    without ``activateWindow()`` the dialog can stay behind the main window.
+    """
+    try:
+        dialog.raise_()
+        dialog.activateWindow()
+    except Exception:
+        pass
+
+
+def stop_thread(thread):
+    """Safely stop and join an Electrum ``TaskThread`` if present.
+
+    The original code commented out thread teardown, leaving background
+    threads running after a dialog closed (which could touch destroyed widgets
+    or keep network connections open until Electrum was restarted).  This
+    stops the thread and waits for it to finish, guarding against ``None`` and
+    any teardown error.
+    """
+    if thread is None:
+        return
+    try:
+        thread.stop()
+    except Exception:
+        pass
+    try:
+        thread.wait()
+    except Exception:
+        pass
+
+
+def show_modal(dialog):
+    """Show *dialog* modally and return the result of ``exec()``.
+
+    Modal dialogs always stay in front of their parent, which is the desired
+    behaviour for the plugin's editing/confirmation dialogs.
+    """
+    try:
+        dialog.setWindowModality(Qt.WindowModality.WindowModal)
+    except Exception:
+        pass
+    bring_to_front(dialog)
+    return dialog.exec()
+
+
+def show_on_top(dialog, *, modal_to_window=True):
+    """Show *dialog* non-modally but guaranteed in front of Electrum.
+
+    Use this for the few dialogs that must remain non-modal (e.g. the
+    transaction dialog the user may want to keep open alongside the wallet).
+    It sets window-modality (so it stays above its parent window without
+    blocking the whole application) and gives it focus.
+
+    Set ``modal_to_window=False`` for a completely modeless window.
+    """
+    try:
+        if modal_to_window:
+            dialog.setWindowModality(Qt.WindowModality.WindowModal)
+        else:
+            dialog.setWindowModality(Qt.WindowModality.NonModal)
+    except Exception:
+        pass
+    dialog.show()
+    bring_to_front(dialog)
+    return dialog