Qt: implement flow layout game grid

This will allow us to properly style the grid and also remove the need to refresh the whole grid on a window resize

rpcs3/rpcs3qt/flow_widget.cpp

@@ -1,8 +1,10 @@
+#include "stdafx.h"
 #include "flow_widget.h"
-#include "flow_layout.h"
 
 #include <QScrollArea>
 #include <QVBoxLayout>
+#include <QStyleOption>
+#include <QPainter>
 
 flow_widget::flow_widget(QWidget* parent)
 	: QWidget(parent)
@@ -11,13 +13,15 @@ flow_widget::flow_widget(QWidget* parent)
 
 	QWidget* widget = new QWidget(this);
 	widget->setLayout(m_flow_layout);
+	widget->setObjectName("flow_widget_content");
+	widget->setFocusProxy(this);
 
-	QScrollArea* scrollArea = new QScrollArea(this);
-	scrollArea->setWidget(widget);
-	scrollArea->setWidgetResizable(true);
+	m_scroll_area = new QScrollArea(this);
+	m_scroll_area->setWidget(widget);
+	m_scroll_area->setWidgetResizable(true);
 
 	QVBoxLayout* layout = new QVBoxLayout(this);
-	layout->addWidget(scrollArea);
+	layout->addWidget(m_scroll_area);
 	layout->setContentsMargins(0, 0, 0, 0);
 	setLayout(layout);
 }
@@ -32,6 +36,9 @@ void flow_widget::add_widget(flow_widget_item* widget)
 	{
 		m_widgets << widget;
 		m_flow_layout->addWidget(widget);
+
+		connect(widget, &flow_widget_item::navigate, this, &flow_widget::on_navigate);
+		connect(widget, &flow_widget_item::focused, this, &flow_widget::on_item_focus);
 	}
 }
 
@@ -46,19 +53,192 @@ QList<flow_widget_item*>& flow_widget::items()
 	return m_widgets;
 }
 
-void flow_widget_item::paintEvent(QPaintEvent* event)
+flow_widget_item* flow_widget::selected_item() const
 {
-	QWidget::paintEvent(event);
-
-	if (!got_visible && cb_on_first_visibility)
+	if (m_selected_index >= 0 && m_selected_index < m_widgets.size())
 	{
-		if (QWidget* widget = static_cast<QWidget*>(parent()))
+		return ::at32(m_widgets, m_selected_index);
+	}
+
+	return nullptr;
+}
+
+QScrollArea* flow_widget::scroll_area() const
+{
+	return m_scroll_area;
+}
+
+void flow_widget::paintEvent(QPaintEvent* /*event*/)
+{
+	// Needed for stylesheets to apply to QWidgets
+	QStyleOption option;
+	option.initFrom(this);
+	QPainter painter(this);
+	style()->drawPrimitive(QStyle::PE_Widget, &option, &painter, this);
+}
+
+int flow_widget::find_item(const flow_layout::position& pos)
+{
+	if (pos.row < 0 || pos.col < 0)
+	{
+		return -1;
+	}
+
+	const auto& positions = m_flow_layout->positions();
+
+	for (int i = 0; i < positions.size(); i++)
+	{
+		if (const auto& other = ::at32(positions, i); other.row == pos.row && other.col == pos.col)
 		{
-			if (widget->visibleRegion().intersects(geometry()))
+			return i;
+		}
+	}
+
+	return -1;
+}
+
+ flow_layout::position flow_widget::find_item(flow_widget_item* item)
+{
+	if (item)
+	{
+		const auto& item_list = m_flow_layout->item_list();
+		const auto& positions = m_flow_layout->positions();
+		ensure(item_list.size() == positions.size());
+
+		for (int i = 0; i < item_list.size(); i++)
+		{
+			if (const auto& layout_item = ::at32(item_list, i); layout_item && layout_item->widget() == item)
 			{
-				got_visible = true;
-				cb_on_first_visibility();
+				return ::at32(positions, i);
 			}
 		}
 	}
+
+	return flow_layout::position{ .row = -1, .col = - 1};
+}
+
+flow_layout::position flow_widget::find_next_item(flow_layout::position current_pos, flow_navigation value)
+{
+	if (current_pos.row >= 0 && current_pos.col >= 0 && m_flow_layout->rows() > 0 && m_flow_layout->cols() > 0)
+	{
+		switch (value)
+		{
+		case flow_navigation::up:
+			// Go up one row.
+			if (current_pos.row > 0)
+			{
+				current_pos.row--;
+			}
+			break;
+		case flow_navigation::down:
+			// Go down one row. Beware of last row which might have less columns.
+			for (const auto& pos : m_flow_layout->positions())
+			{;
+				if (pos.col != current_pos.col) continue;
+				if (pos.row == current_pos.row + 1)
+				{
+					current_pos.row = pos.row;
+					break;
+				}
+			}
+			break;
+		case flow_navigation::left:
+			// Go left one column.
+			if (current_pos.col > 0)
+			{
+				current_pos.col--;
+			}
+			break;
+		case flow_navigation::right:
+			// Go right one column. Beware of last row which might have less columns.
+			for (const auto& pos : m_flow_layout->positions())
+			{
+				if (pos.row > current_pos.row) break;
+				if (pos.row < current_pos.row) continue;
+				if (pos.col == current_pos.col + 1)
+				{
+					current_pos.col = pos.col;
+					break;
+				}
+			}
+			break;
+		case flow_navigation::home:
+			// Go to leftmost column.
+			current_pos.col = 0;
+			break;
+		case flow_navigation::end:
+			// Go to last column. Beware of last row which might have less columns.
+			for (const auto& pos : m_flow_layout->positions())
+			{
+				if (pos.row > current_pos.row) break;
+				if (pos.row < current_pos.row) continue;
+				current_pos.col = std::max(current_pos.col, pos.col);
+			}
+			break;
+		case flow_navigation::page_up:
+			// Go to top row.
+			current_pos.row = 0;
+			break;
+		case flow_navigation::page_down:
+			// Go to bottom row. Beware of last row which might have less columns.
+			for (const auto& pos : m_flow_layout->positions())
+			{
+				if (pos.col != current_pos.col) continue;
+				current_pos.row = std::max(current_pos.row, pos.row);
+			}
+			break;
+		}
+	}
+
+	return current_pos;
+}
+
+void flow_widget::select_item(flow_widget_item* item)
+{
+	const flow_layout::position selected_pos = find_item(item);
+	const int selected_index = find_item(selected_pos);
+
+	if (selected_index < 0 || selected_index >= items().size())
+	{
+		m_selected_index = -1;
+		return;
+	}
+
+	m_selected_index = selected_index;
+	Q_EMIT ItemSelectionChanged(m_selected_index);
+
+	for (int i = 0; i < items().size(); i++)
+	{
+		if (flow_widget_item* item = items().at(i))
+		{
+			// We need to polish the widgets in order to re-apply any stylesheet changes for the selected property.
+			item->selected = i == m_selected_index;
+			item->polish_style();
+		}
+	}
+
+	// Make sure we see the focused widget
+	m_scroll_area->ensureWidgetVisible(::at32(items(), m_selected_index));
+}
+
+void flow_widget::on_item_focus()
+{
+	select_item(static_cast<flow_widget_item*>(QObject::sender()));
+}
+
+void flow_widget::on_navigate(flow_navigation value)
+{
+	const flow_layout::position selected_pos = find_next_item(find_item(static_cast<flow_widget_item*>(QObject::sender())), value);
+	const int selected_index = find_item(selected_pos);
+	if (selected_index < 0 || selected_index >= items().size())
+	{
+		return;
+	}
+
+	if (flow_widget_item* item = items().at(selected_index))
+	{
+		item->setFocus();
+	}
+
+	m_selected_index = selected_index;
 }