From 0f7443f0109c4e914eb31437fa689f45b525de19 Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Sun, 4 Apr 2021 20:46:46 +0200
Subject: [PATCH] SystemMonitor: Add a status bar to the main window

To get us started, this shows the number of processes and threads in
the last captured state.
---
 .../Applications/SystemMonitor/ProcessModel.cpp    |  3 +++
 Userland/Applications/SystemMonitor/ProcessModel.h |  1 +
 Userland/Applications/SystemMonitor/main.cpp       | 14 +++++++++++---
 3 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/Userland/Applications/SystemMonitor/ProcessModel.cpp b/Userland/Applications/SystemMonitor/ProcessModel.cpp
index 51894ac2693..da7251d1c4e 100644
--- a/Userland/Applications/SystemMonitor/ProcessModel.cpp
+++ b/Userland/Applications/SystemMonitor/ProcessModel.cpp
@@ -429,6 +429,9 @@ void ProcessModel::update()
     if (on_cpu_info_change)
         on_cpu_info_change(m_cpus);
 
+    if (on_state_update)
+        on_state_update(all_processes->size(), m_threads.size());
+
     // FIXME: This is a rather hackish way of invalidating indexes.
     //        It would be good if GUI::Model had a way to orchestrate removal/insertion while preserving indexes.
     did_update(previous_tid_count == m_tids.size() ? GUI::Model::UpdateFlag::DontInvalidateIndexes : GUI::Model::UpdateFlag::InvalidateAllIndexes);
diff --git a/Userland/Applications/SystemMonitor/ProcessModel.h b/Userland/Applications/SystemMonitor/ProcessModel.h
index 803b9bdfcd2..1c664c4dece 100644
--- a/Userland/Applications/SystemMonitor/ProcessModel.h
+++ b/Userland/Applications/SystemMonitor/ProcessModel.h
@@ -94,6 +94,7 @@ public:
     };
 
     Function<void(const NonnullOwnPtrVector<CpuInfo>&)> on_cpu_info_change;
+    Function<void(int process_count, int thread_count)> on_state_update;
 
     const NonnullOwnPtrVector<CpuInfo>& cpus() const { return m_cpus; }
 
diff --git a/Userland/Applications/SystemMonitor/main.cpp b/Userland/Applications/SystemMonitor/main.cpp
index b684ecea84c..f9b4c36068b 100644
--- a/Userland/Applications/SystemMonitor/main.cpp
+++ b/Userland/Applications/SystemMonitor/main.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
+ * Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -51,6 +51,7 @@
 #include <LibGUI/Painter.h>
 #include <LibGUI/SortingProxyModel.h>
 #include <LibGUI/Splitter.h>
+#include <LibGUI/StatusBar.h>
 #include <LibGUI/TabWidget.h>
 #include <LibGUI/TableView.h>
 #include <LibGUI/ToolBar.h>
@@ -174,10 +175,17 @@ int main(int argc, char** argv)
     auto& keeper = window->set_main_widget<GUI::Widget>();
     keeper.set_layout<GUI::VerticalBoxLayout>();
     keeper.set_fill_with_background_color(true);
-    keeper.layout()->set_margins({ 2, 2, 2, 2 });
+    keeper.layout()->set_margins({ 2, 2, 2, 0 });
 
     auto& tabwidget = keeper.add<GUI::TabWidget>();
 
+    auto& statusbar = keeper.add<GUI::StatusBar>(2);
+    auto process_model = ProcessModel::create();
+    process_model->on_state_update = [&](int process_count, int thread_count) {
+        statusbar.set_text(0, String::formatted("Processes: {}", process_count));
+        statusbar.set_text(1, String::formatted("Threads: {}", thread_count));
+    };
+
     auto process_container_splitter = GUI::VerticalSplitter::construct();
     tabwidget.add_widget("Processes", process_container_splitter);
     process_container_splitter->layout()->set_margins({ 4, 4, 4, 4 });
@@ -210,7 +218,7 @@ int main(int argc, char** argv)
 
     auto& process_table_view = process_table_container.add<GUI::TableView>();
     process_table_view.set_column_headers_visible(true);
-    process_table_view.set_model(GUI::SortingProxyModel::create(ProcessModel::create()));
+    process_table_view.set_model(GUI::SortingProxyModel::create(process_model));
     process_table_view.set_key_column_and_sort_order(ProcessModel::Column::CPU, GUI::SortOrder::Descending);
     process_table_view.model()->update();