From aecc153966f682ec38a10277ec4abf0da7642a0a Mon Sep 17 00:00:00 2001
From: Tsu Jan <tsujan2000@gmail.com>
Date: Thu, 28 Nov 2024 15:58:06 +0330
Subject: [PATCH] Put dropdown window on active screen under Wayland

All complex problems in implementing this feature were caused by resizing the window programmatically on Wayland, as was done on X11. This patch sets 4 anchors instead, and then sets the left, right and bottom margins properly on showing the window.

Fixes https://github.com/lxqt/qterminal/issues/1142
---
 src/mainwindow.cpp | 39 ++++++++++++++++++++++++++++++++-------
 src/mainwindow.h   |  5 +++++
 2 files changed, 37 insertions(+), 7 deletions(-)

diff --git a/src/mainwindow.cpp b/src/mainwindow.cpp
index 10290604..3fe1c317 100644
--- a/src/mainwindow.cpp
+++ b/src/mainwindow.cpp
@@ -69,7 +69,8 @@ MainWindow::MainWindow(TerminalConfig &cfg,
       presetsMenu(nullptr),
       m_config(cfg),
       m_dropLockButton(nullptr),
-      m_dropMode(dropMode)
+      m_dropMode(dropMode),
+      m_layerWindow(nullptr)
 {
 #ifdef HAVE_QDBUS
     registerAdapter<WindowAdaptor, MainWindow>(this);
@@ -176,12 +177,17 @@ void MainWindow::enableDropMode()
         winId();
         if (QWindow *win = windowHandle())
         {
-            if (LayerShellQt::Window* layershell = LayerShellQt::Window::get(win))
+            m_layerWindow = LayerShellQt::Window::get(win);
+            if (m_layerWindow)
             {
-                layershell->setLayer(LayerShellQt::Window::Layer::LayerOverlay);
-                layershell->setKeyboardInteractivity(LayerShellQt::Window::KeyboardInteractivityOnDemand);
-                LayerShellQt::Window::Anchors anchors = {LayerShellQt::Window::AnchorTop};
-                layershell->setAnchors(anchors);
+                m_layerWindow->setLayer(LayerShellQt::Window::Layer::LayerOverlay);
+                m_layerWindow->setKeyboardInteractivity(LayerShellQt::Window::KeyboardInteractivityOnDemand);
+                LayerShellQt::Window::Anchors anchors = {LayerShellQt::Window::AnchorTop
+                                                         | LayerShellQt::Window::AnchorBottom
+                                                         | LayerShellQt::Window::AnchorLeft
+                                                         | LayerShellQt::Window::AnchorRight};
+                m_layerWindow->setAnchors(anchors);
+                m_layerWindow->setScreenConfiguration(LayerShellQt::Window::ScreenConfiguration::ScreenFromCompositor);
             }
         }
     }
@@ -757,9 +763,15 @@ void MainWindow::realign()
 {
     if (m_dropMode)
     {
+        if (m_layerWindow)
+        {
+            return; // done in showEvent
+        }
         QScreen *appScreen = QGuiApplication::screenAt(QCursor::pos());
         if(appScreen == nullptr)
+        {
             appScreen = QGuiApplication::primaryScreen();
+        }
         const QRect desktop = appScreen->availableGeometry();
         QRect g = QRect(desktop.x(),
                         desktop.y(),
@@ -768,7 +780,8 @@ void MainWindow::realign()
         g.moveCenter(desktop.center());
         // do not use 0 here - we need to calculate with potential panel on top
         g.moveTop(desktop.top());
-        if (g != geometry()) {
+        if (g != geometry())
+        {
             setGeometry(g);
         }
     }
@@ -871,6 +884,18 @@ bool MainWindow::event(QEvent *event)
     return QMainWindow::event(event);
 }
 
+void MainWindow::showEvent(QShowEvent* event)
+{
+    if (m_dropMode && m_layerWindow)
+    {
+        const QRect desktop = windowHandle()->screen()->availableGeometry();
+        int hMargin = desktop.width() * (100 - Properties::Instance()->dropWidth) / 200;
+        int vMargin = desktop.height() * (100 - Properties::Instance()->dropHeight) / 100;
+        m_layerWindow->setMargins(QMargins(hMargin, 0, hMargin, vMargin));
+    }
+    QMainWindow::showEvent(event);
+}
+
 void MainWindow::newTerminalWindow()
 {
     TerminalConfig cfg;
diff --git a/src/mainwindow.h b/src/mainwindow.h
index 4a353831..e67baed0 100644
--- a/src/mainwindow.h
+++ b/src/mainwindow.h
@@ -28,6 +28,9 @@
 #include "terminalconfig.h"
 #include "dbusaddressable.h"
 
+namespace LayerShellQt {
+    class Window;
+}
 
 class QToolButton;
 
@@ -55,6 +58,7 @@ class MainWindow : public QMainWindow, private Ui::mainWindow, public DBusAddres
 
 protected:
      bool event(QEvent* event) override;
+     void showEvent(QShowEvent* event) override;
 
 private:
     QActionGroup *tabPosition, *scrollBarPosition, *keyboardCursorShape;
@@ -86,6 +90,7 @@ class MainWindow : public QMainWindow, private Ui::mainWindow, public DBusAddres
     void enableDropMode();
     QToolButton *m_dropLockButton;
     bool m_dropMode;
+    LayerShellQt::Window *m_layerWindow;
     QxtGlobalShortcut m_dropShortcut;
     void realign();
     void setDropShortcut(const QKeySequence& dropShortCut);