GUI: Add ability to start & stop transcription engine

4 files changed, 137 insertions, 3 deletions

diff --git a/GUI/GUI/GUI/Frame.cpp b/GUI/GUI/GUI/Frame.cpp
index 74683ca..db2bdd7 100644
--- a/GUI/GUI/GUI/Frame.cpp
+++ b/GUI/GUI/GUI/Frame.cpp
@@ -10,6 +10,8 @@ namespace {
         ID_PY_PANEL,

         ID_PY_VERSION_BUTTON,

         ID_PY_SETUP_BUTTON,

+        ID_PY_APP_START_BUTTON,

+        ID_PY_APP_STOP_BUTTON,

         ID_PY_OUT,

     };

 };

@@ -20,11 +22,16 @@ Frame::Frame()
 	py_panel_sizer_(wxVERTICAL),

 	py_version_button_(&py_panel_, ID_PY_VERSION_BUTTON, "Check embedded Python version"),

 	py_setup_button_(&py_panel_, ID_PY_SETUP_BUTTON, "Set up Python virtual environment"),

+	py_app_start_button_(&py_panel_, ID_PY_APP_START_BUTTON, "Begin transcribing"),

+	py_app_stop_button_(&py_panel_, ID_PY_APP_STOP_BUTTON, "Stop transcribing"),

 	py_out_(&py_panel_, ID_PY_OUT, wxEmptyString, wxDefaultPosition,

-        wxSize(/*x_px=*/480, /*y_px=*/160), wxTE_MULTILINE)

+		wxSize(/*x_px=*/480, /*y_px=*/160), wxTE_MULTILINE),

+	py_app_(nullptr)

 {

 	Bind(wxEVT_MENU, &Frame::OnExit, this, wxID_EXIT);

 	Bind(wxEVT_BUTTON, &Frame::OnGetPythonVersion, this, ID_PY_VERSION_BUTTON);

+	Bind(wxEVT_BUTTON, &Frame::OnAppStart, this, ID_PY_APP_START_BUTTON);

+	Bind(wxEVT_BUTTON, &Frame::OnAppStop, this, ID_PY_APP_STOP_BUTTON);

 	Bind(wxEVT_BUTTON, &Frame::OnSetupPython, this, ID_PY_SETUP_BUTTON);

 

 	// wx needs this to be able to load PNGs.

@@ -38,6 +45,8 @@ Frame::Frame()
 	py_panel_.SetSizer(&py_panel_sizer_);

     py_panel_sizer_.Add(&py_version_button_);

     py_panel_sizer_.Add(&py_setup_button_);

+    py_panel_sizer_.Add(&py_app_start_button_);

+    py_panel_sizer_.Add(&py_app_stop_button_);

     py_panel_sizer_.Add(&py_out_);

 }

 

@@ -60,8 +69,8 @@ void Frame::OnSetupPython(wxCommandEvent& event)
     py_out_.AppendText("Setting up Python virtual environment\n");

     py_out_.AppendText("This could take several minutes, please be patient!\n");

     py_out_.AppendText("This will download ~5GB of dependencies.\n");

-    py_out_.AppendText("Dependencies are installed in the executable folder, "

-        "so deleting the folder is all that's needed to undo this.");

+    py_out_.AppendText("Dependencies are installed in the GUI's folder, "

+        "so deleting the folder is all that's needed to uninstall.\n");

 

     {

         std::string py_out;

@@ -107,6 +116,74 @@ void Frame::OnSetupPython(wxCommandEvent& event)
     py_out_.AppendText("Python virtual environment successfully set up!\n");

 }

 

+void Frame::OnAppStart(wxCommandEvent& event) {

+    if (py_app_) {

+        if (wxProcess::Exists(py_app_->GetPid())) {

+            py_out_.AppendText("Transcription engine already running\n");

+            return;

+        }

+        delete py_app_;

+        py_app_ = nullptr;

+    }

+

+	py_out_.AppendText("Launching transcription engine\n");

+

+    PythonWrapper py;

+    auto cb = [&](wxProcess* proc, int ret) -> void {

+		std::ostringstream py_out_oss;

+        py_out_oss << "Transcription engine exited with code " << ret << std::endl;

+

+		py_out_.AppendText(py_out_oss.str());

+		return;

+    };

+

+    wxProcess* p = py.StartApp(std::move(cb));

+    if (!p) {

+        py_out_.AppendText("Failed to launch transcription engine\n");

+        return;

+    }

+

+    py_app_ = p;

+}

+

+void Frame::OnAppStop(wxCommandEvent& event) {

+    if (py_app_) {

+        const long pid = py_app_->GetPid();

+

+        // Try to kill it politely.

+        wxProcess::Kill(pid);

+        for (int i = 0; i < 10; i++) {

+            if (!wxProcess::Exists(pid)) {

+                break;

+            }

+            wxMilliSleep(10);

+        }

+

+        // If it doesn't accept its fate, murder it with an axe.

+		bool first = true;

+        int loop_cnt = 0;

+		while (wxProcess::Exists(pid)) {

+			if (first) {

+				first = false;

+				py_out_.AppendText("Timed out trying to stop transcription engine "

+					"cleanly, sending SIGKILL\n");

+			}

+			else if (++loop_cnt % 100 == 0) {

+                    py_out_.AppendText("Waiting for transcription engine to exit");

+			}

+			wxProcess::Kill(pid, wxSIGKILL);

+			wxMilliSleep(10);

+        }

+

+        // Since we don't process the termination event, py_app_ deletes itself!

+        py_app_ = nullptr;

+        py_out_.AppendText("Stopped transcription engine\n");

+    }

+    else {

+        py_out_.AppendText("Transcription engine already stopped\n");

+    }

+}

+

 void Frame::LoadAndSetIcon(const std::string& icon_path) {

     if (!std::filesystem::exists(icon_path)) {

         wxLogFatalError("Logo is missing from %s", icon_path.c_str());

diff --git a/GUI/GUI/GUI/Frame.h b/GUI/GUI/GUI/Frame.h
index 62e9169..414d2b3 100644
--- a/GUI/GUI/GUI/Frame.h
+++ b/GUI/GUI/GUI/Frame.h
@@ -6,6 +6,8 @@
 #include <wx/wx.h>

 #endif

 

+#include <memory>

+

 class Frame : public wxFrame

 {

 public:

@@ -17,11 +19,17 @@ private:
     wxBoxSizer py_panel_sizer_;

     wxButton py_version_button_;

     wxButton py_setup_button_;

+    wxButton py_app_start_button_;

+    wxButton py_app_stop_button_;

     wxTextCtrl py_out_;

 

+    wxProcess* py_app_;

+

     void OnExit(wxCommandEvent& event);

     void OnGetPythonVersion(wxCommandEvent& event);

     void OnSetupPython(wxCommandEvent& event);

+    void OnAppStart(wxCommandEvent& event);

+    void OnAppStop(wxCommandEvent& event);

 

     void LoadAndSetIcon(const std::string& icon_path);

 };

diff --git a/GUI/GUI/GUI/PythonWrapper.cpp b/GUI/GUI/GUI/PythonWrapper.cpp
index 27d12fd..7270ab5 100644
--- a/GUI/GUI/GUI/PythonWrapper.cpp
+++ b/GUI/GUI/GUI/PythonWrapper.cpp
@@ -4,6 +4,38 @@
 
 #include <sstream>
 
+class PythonProcess : public wxProcess {
+public:
+	PythonProcess(std::function<void(wxProcess* proc, int ret)>&& exit_callback) : exit_cb_(exit_callback) {}
+
+	virtual void OnTerminate(int pid, int status) wxOVERRIDE {
+		exit_cb_(this, status);
+	}
+
+private:
+	const std::function<void(wxProcess* proc, int ret)> exit_cb_;
+};
+
+wxProcess* PythonWrapper::InvokeAsyncWithArgs(std::vector<std::string>&& args,
+	std::function<void(wxProcess* proc, int ret)>&& exit_callback) {
+	std::ostringstream cmd_oss;
+	cmd_oss << "Resources/Python/python.exe";
+	for (const auto& arg : args) {
+		cmd_oss << " " << arg;
+	}
+
+	auto *p = new PythonProcess(std::move(exit_callback));
+	// TODO(yum) we should hide the console & stream output to a friendlier interface
+	int pid = wxExecute(cmd_oss.str(), wxEXEC_ASYNC, p);
+
+	if (!pid) {
+		delete p;
+		p = nullptr;
+	}
+
+	return p;
+}
+
 bool PythonWrapper::InvokeWithArgs(std::vector<std::string>&& args, std::string* out) {
 	std::ostringstream cmd_oss;
 	cmd_oss << "Resources/Python/python.exe";
@@ -52,3 +84,9 @@ bool PythonWrapper::InstallPip(std::string* out) {
 	std::string pip_path = "Resources/Python/get-pip.py";
     return InvokeWithArgs({ pip_path }, out);
 }
+
+wxProcess* PythonWrapper::StartApp(std::function<void(wxProcess* proc, int ret)>&& exit_callback) {
+	return InvokeAsyncWithArgs({ "Resources/Scripts/transcribe.py" },
+		std::move(exit_callback));
+}
+
diff --git a/GUI/GUI/GUI/PythonWrapper.h b/GUI/GUI/GUI/PythonWrapper.h
index 607507d..4407b5e 100644
--- a/GUI/GUI/GUI/PythonWrapper.h
+++ b/GUI/GUI/GUI/PythonWrapper.h
@@ -6,6 +6,8 @@
 #include <wx/wx.h>
 #endif
 
+#include <wx/process.h>
+
 #include <string>
 #include <vector>
 
@@ -15,6 +17,13 @@
 class PythonWrapper
 {
 public:
+
+	// Invoke the interpreter asynchronously with the given arguments.
+	// When the process exits, `exit_callback` runs.
+	// The caller is responsible for deleting wxProcess.
+	wxProcess* InvokeAsyncWithArgs(std::vector<std::string>&& args,
+		std::function<void(wxProcess* proc, int ret)>&& exit_callback);
+
 	// Invoke the interpreter with arguments.
 	// On error, sets `out` to an error message and returns false.
 	bool InvokeWithArgs(std::vector<std::string>&& args, std::string* out);
@@ -24,5 +33,7 @@ public:
 
 	// Execute get-pip.py.
 	bool InstallPip(std::string* out);
+
+	wxProcess* StartApp(std::function<void(wxProcess* proc, int ret)>&& exit_callback);
 };