Preferecnes: add the initial skeleton

This Preferences dialog should be visually similar to the
old one - the main difference is how it acts on the preferences.
It's also not based on .ui files since it's a very simple widget
I prefered to mount it by hand - no more than 6 lines of c++ code.

Right now we have only one preference page on this, and nothing
is hoocked up.

I've also changed mainwindow a bit to only show this dialog for
testing purposes.

Signed-off-by: Tomaz Canabrava <tomaz.canabrava@intel.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

desktop-widgets/preferences/preferencesdialog.cpp

@@ -0,0 +1,83 @@
+#include "preferencesdialog.h"
+
+#include "abstractpreferenceswidget.h"
+#include "preferences_language.h"
+
+#include <QVBoxLayout>
+#include <QHBoxLayout>
+#include <QListWidget>
+#include <QStackedWidget>
+#include <QDialogButtonBox>
+
+PreferencesDialogV2::PreferencesDialogV2()
+{
+	pagesList = new QListWidget();
+	pagesStack = new QStackedWidget();
+	buttonBox = new QDialogButtonBox(QDialogButtonBox::Apply|QDialogButtonBox::RestoreDefaults|QDialogButtonBox::Cancel);
+
+	pagesList->setMinimumWidth(120);
+	pagesList->setMaximumWidth(120);
+
+	QHBoxLayout *h = new QHBoxLayout();
+	h->addWidget(pagesList);
+	h->addWidget(pagesStack);
+
+	QVBoxLayout *v = new QVBoxLayout();
+	v->addLayout(h);
+	v->addWidget(buttonBox);
+
+	setLayout(v);
+	
+	addPreferencePage(new PreferencesLanguage());
+	refreshPages();
+	connect(pagesList, &QListWidget::currentRowChanged,
+		pagesStack, &QStackedWidget::setCurrentIndex);
+}
+
+PreferencesDialogV2::~PreferencesDialogV2()
+{
+}
+
+bool abstractpreferenceswidget_lessthan(AbstractPreferencesWidget *p1, AbstractPreferencesWidget *p2)
+{
+	return p1->positionHeight() <= p2->positionHeight();
+}
+
+void PreferencesDialogV2::addPreferencePage(AbstractPreferencesWidget *page)
+{
+	pages.push_back(page);
+	qSort(pages.begin(), pages.end(), abstractpreferenceswidget_lessthan);
+}
+
+void PreferencesDialogV2::refreshPages()
+{
+	// Remove things
+	pagesList->clear();
+	while(pagesStack->count()) {
+		QWidget *curr = pagesStack->widget(0);
+		pagesStack->removeWidget(curr);
+		curr->setParent(0);
+	}
+
+	// Readd things.
+	Q_FOREACH(AbstractPreferencesWidget *page, pages) {
+		QListWidgetItem *item = new QListWidgetItem(page->icon(), page->name());
+		pagesList->addItem(item);
+		pagesStack->addWidget(page);
+	}
+}
+
+void PreferencesDialogV2::applyRequested()
+{
+	//TODO
+}
+
+void PreferencesDialogV2::cancelRequested()
+{
+	//TODO
+}
+
+void PreferencesDialogV2::defaultsRequested()
+{
+	//TODO
+}