Terminal: Lazily open remote terminals

Move the burden of finding the shell of a device from the shell menu
to the TerminalWidget, so that opening the shell menu does not block
the ui.

Change-Id: I7f2e5a891f20faa53a1e3eec879866219f9bee0b
Reviewed-by: hjk <hjk@qt.io>

src/plugins/terminal/shellmodel.cpp

@@ -3,6 +3,9 @@
 
 #include "shellmodel.h"
 
+#include <projectexplorer/devicesupport/devicemanager.h>
+#include <projectexplorer/projectexplorerconstants.h>
+
 #include <utils/algorithm.h>
 #include <utils/environment.h>
 #include <utils/filepath.h>
@@ -138,11 +141,10 @@ ShellModelPrivate::ShellModelPrivate()
         });
 
         // ... and filter out non-existing shells.
-        localShells = Utils::transform(
-                    Utils::filtered(shells, [](const FilePath &shell) {return shell.exists(); }),
-                    [&iconProvider](const FilePath &shell) {
-            return ShellItemBuilder(iconProvider, shell).item();
-        });
+        localShells = Utils::transform(Utils::filtered(shells, &FilePath::exists),
+                                       [&iconProvider](const FilePath &shell) {
+                                           return ShellItemBuilder(iconProvider, shell).item();
+                                       });
     }
 }
 
@@ -161,14 +163,15 @@ QList<ShellModelItem> ShellModel::local() const
 
 QList<ShellModelItem> ShellModel::remote() const
 {
-    const auto deviceCmds = Utils::Terminal::Hooks::instance().getTerminalCommandsForDevicesHook()();
+    QList<ShellModelItem> result;
 
-    const QList<ShellModelItem> deviceItems = Utils::transform(
-        deviceCmds, [](const Utils::Terminal::NameAndCommandLine &item) -> ShellModelItem {
-            return ShellModelItem{item.name, {item.commandLine}};
+    ProjectExplorer::DeviceManager::instance()->forEachDevice(
+        [&result](const QSharedPointer<const ProjectExplorer::IDevice> &device) {
+            if (device->type() != ProjectExplorer::Constants::DESKTOP_DEVICE_TYPE)
+                result << ShellModelItem{device->displayName(), {{device->rootPath(), {}}}};
         });
 
-    return deviceItems;
+    return result;
 }
 
 } // namespace Terminal::Internal

src/plugins/terminal/terminalwidget.cpp

@@ -16,6 +16,7 @@
 #include <coreplugin/messagemanager.h>
 
 #include <utils/algorithm.h>
+#include <utils/async.h>
 #include <utils/environment.h>
 #include <utils/fileutils.h>
 #include <utils/hostosinfo.h>
@@ -82,6 +83,33 @@ void TerminalWidget::setupPty()
     CommandLine shellCommand = m_openParameters.shellCommand.value_or(
         CommandLine{settings().shell(), settings().shellArguments(), CommandLine::Raw});
 
+    if (shellCommand.executable().isRootPath()) {
+        writeToTerminal(Tr::tr("Connecting ...\r\n").toUtf8(), true);
+        // We still have to find the shell to start ...
+        m_findShellWatcher.reset(new QFutureWatcher<FilePath>());
+        connect(m_findShellWatcher.get(), &QFutureWatcher<FilePath>::finished, this, [this] {
+            const FilePath result = m_findShellWatcher->result();
+            if (!result.isEmpty()) {
+                m_openParameters.shellCommand->setExecutable(m_findShellWatcher->result());
+                restart(m_openParameters);
+                return;
+            }
+
+            writeToTerminal(
+                ("\r\n\033[31m" + Tr::tr("Could not find shell to start.") + "\r\n").toUtf8(), true);
+        });
+
+        m_findShellWatcher->setFuture(Utils::asyncRun([shellCommand] {
+            const FilePath result = Utils::Terminal::defaultShellForDevice(
+                shellCommand.executable());
+            if (result.isExecutableFile())
+                return result;
+            return FilePath{};
+        }));
+
+        return;
+    }
+
     Environment env = m_openParameters.environment.value_or(Environment{})
                           .appliedToEnvironment(shellCommand.executable().deviceEnvironment());
 

src/plugins/terminal/terminalwidget.h

@@ -16,6 +16,10 @@
 #include <utils/process.h>
 #include <utils/terminalhooks.h>
 
+#include <QFutureWatcher>
+
+#include <memory>
+
 namespace Terminal {
 
 using RegisteredAction = std::unique_ptr<QAction, std::function<void(QAction *)>>;
@@ -105,6 +109,8 @@ private:
     RegisteredAction m_close;
 
     Internal::ShortcutMap m_shortcutMap;
+
+    std::unique_ptr<QFutureWatcher<Utils::FilePath>> m_findShellWatcher;
 };
 
 } // namespace Terminal