Add a very experimental QT based runtime for pgAdmin 4.

This runtime implements a brower control with embedded Python
interpretor. The Python interpretor runs a simple script at
startup to generate some HTML that is displayed in the browser.
Arbitrary URLs can be opened from the "Open URL" option on the
File menu.

runtime/BrowserWindow.cpp

@@ -0,0 +1,131 @@
+//////////////////////////////////////////////////////////////////////////
+//
+// pgAdmin 4 - PostgreSQL Tools
+//
+// Copyright (C) 2013, The pgAdmin Development Team
+// This software is released under the PostgreSQL Licence
+//
+// BrowserWindow.cpp - Implementation of the main window class
+//
+//////////////////////////////////////////////////////////////////////////
+
+// Must be before QT
+#include <Python.h>
+
+#include <QtGlobal>
+
+#if QT_VERSION >= 0x050000
+#include <QtWidgets>
+#include <QtWebKitWidgets>
+#else
+#include <QtWebKit>
+#include <QAction>
+#include <QMenu>
+#include <QMenuBar>
+#include <QMessageBox>
+#include <QInputDialog>
+#include <QLineEdit>
+#endif
+
+#include "BrowserWindow.h"
+
+// Constructor
+BrowserWindow::BrowserWindow()
+{
+    createActions();
+    createMenus();
+
+    // Create the WebKit control
+    webView = new QWebView(this);
+    setCentralWidget(webView);
+
+    // Execute some python and set the web text
+    QString data = execPython(tr("from time import time,ctime\n"
+                                 "print 'Today is <b>%s</b><br /><i>This is python-generated HTML.</i>' % ctime(time())\n"));
+
+    webView->setHtml(data);
+}
+
+// Create the actions for the window
+void BrowserWindow::createActions()
+{
+    // Open an arbitrary URL
+    openUrlAction = new QAction(tr("&Open URL..."), this);
+    openUrlAction->setShortcut(tr("Ctrl+U"));
+    openUrlAction->setStatusTip(tr("Open a URL"));
+    connect(openUrlAction, SIGNAL(triggered()), this, SLOT(openUrl()));
+
+    // Exit the app
+    exitAction = new QAction(tr("E&xit"), this);
+    exitAction->setStatusTip(tr("Exit the application"));
+    exitAction->setShortcuts(QKeySequence::Quit);
+    connect(exitAction, SIGNAL(triggered()), this, SLOT(close()));
+
+    // About box
+    aboutAction = new QAction(tr("&About"), this);
+    aboutAction->setStatusTip(tr("Show the application's About box"));
+    connect(aboutAction, SIGNAL(triggered()), this, SLOT(about()));
+}
+
+// Create the application menus
+void BrowserWindow::createMenus()
+{
+    // File
+    fileMenu = menuBar()->addMenu(tr("&File"));
+    fileMenu->addAction(openUrlAction);
+    fileMenu->addSeparator();
+    fileMenu->addAction(exitAction);
+
+    menuBar()->addSeparator();
+
+    // Help
+    helpMenu = menuBar()->addMenu(tr("&Help"));
+    helpMenu->addAction(aboutAction);
+}
+
+// Display the about box
+void BrowserWindow::about()
+{
+    QMessageBox::about(this, tr("About pgAdmin 4"), tr("pgAdmin 4 - PostgreSQL Tools"));
+}
+
+// Open an arbitrary URL
+void BrowserWindow::openUrl()
+{
+    bool ok;
+    QString url = QInputDialog::getText(this, tr("Enter a URL"), tr("URL:"), QLineEdit::Normal, "http://", &ok);
+
+    if (ok && !url.isEmpty())
+        webView->setUrl(url);
+}
+
+QString BrowserWindow::execPython(QString script)
+{
+    // This python script allows us to capture stdout/stderr
+    QString stdOutErr =
+tr("import sys\n\
+class CatchStdoutStderr:\n\
+    def __init__(self):\n\
+        self.op = ''\n\
+    def write(self, txt):\n\
+        self.op += txt\n\
+catchStdoutStderr = CatchStdoutStderr()\n\
+sys.stdout = catchStdoutStderr\n\
+sys.stderr = catchStdoutStderr\n\
+");
+
+    // Create the main module, and call the redirect code.
+    PyObject *pModule = PyImport_AddModule("__main__");
+    PyRun_SimpleString(stdOutErr.toUtf8().constData());
+
+    // Now execute the actual script
+    PyRun_SimpleString(script.toUtf8().constData());
+
+    // Get the catcher object
+    PyObject *catcher = PyObject_GetAttrString(pModule,"catchStdoutStderr");
+    PyErr_Print();
+
+    PyObject *output = PyObject_GetAttrString(catcher,"op");
+
+    return QString(PyString_AsString(output));
+}