[PATCH 04/11] [HiDPI] Make TableView resolution independent

[Giuseppe Bilotta]

Don't hard-code column widths or icon sizes/positions. Instead, compute
them from the fonts used.

Signed-off-by: Giuseppe Bilotta <giuseppe.bilotta at gmail.com>
---
 qt-ui/tableview.cpp | 37 ++++++++++++++++++++++++++++++-------
 qt-ui/tableview.h   | 11 +++++++++++
 2 files changed, 41 insertions(+), 7 deletions(-)

diff --git a/qt-ui/tableview.cpp b/qt-ui/tableview.cpp
index a56ab47..a654e3c 100644
--- a/qt-ui/tableview.cpp
+++ b/qt-ui/tableview.cpp
@@ -12,16 +12,34 @@ TableView::TableView(QWidget *parent) : QWidget(parent)
 {
 	ui.setupUi(this);
 	ui.tableView->setItemDelegate(new DiveListDelegate(this));
+
+	QFontMetrics fm(defaultModelFont());
+	int text_ht = fm.height();
+	int text_em = fm.width('m');
+	// icon size is the closest multiple of 16 to the font height
+	metrics.icon_size = (text_ht + 8)/16;
+	metrics.icon_size *= 16;
+	// enforce a minimum size
+	if (metrics.icon_size < 16)
+		metrics.icon_size = 16;
+	metrics.btn_size = metrics.icon_size + metrics.icon_size/2;
+	metrics.btn_gap = metrics.icon_size/8;
+
+	metrics.col_width = 7*text_em;
+	metrics.rm_col_width = 3*text_em;
+	metrics.header_ht = text_ht + 10; // TODO DPI
+
 	/* There`s mostly a need for a Mac fix here too. */
 	if (qApp->style()->objectName() == "gtk+")
 		ui.groupBox->layout()->setContentsMargins(0, 9, 0, 0);
 	else
 		ui.groupBox->layout()->setContentsMargins(0, 0, 0, 0);
+
 	QIcon plusIcon(":plus");
 	plusBtn = new QPushButton(plusIcon, QString(), ui.groupBox);
 	plusBtn->setFlat(true);
 	plusBtn->setToolTip(tr("Add cylinder"));
-	plusBtn->setIconSize(QSize(16, 16));
+	plusBtn->setIconSize(QSize(metrics.icon_size, metrics.icon_size));
 	connect(plusBtn, SIGNAL(clicked(bool)), this, SIGNAL(addButtonClicked()));
 }
 
@@ -39,8 +57,7 @@ TableView::~TableView()
 		s.remove("");
 	} else {
 		for (int i = 0; i < ui.tableView->model()->columnCount(); i++) {
-			if ((i == CylindersModel::REMOVE && ui.tableView->columnWidth(i) == 30) ||
-			    ui.tableView->columnWidth(i) == 70)
+			if (ui.tableView->columnWidth(i) == defaultColumnWidth(i))
 				s.remove(QString("colwidth%1").arg(i));
 			else
 				s.setValue(QString("colwidth%1").arg(i), ui.tableView->columnWidth(i));
@@ -68,18 +85,19 @@ void TableView::setModel(QAbstractItemModel *model)
 	s.beginGroup(objectName());
 	const int columnCount = ui.tableView->model()->columnCount();
 	for (int i = 0; i < columnCount; i++) {
-		QVariant width = s.value(QString("colwidth%1").arg(i), i == CylindersModel::REMOVE ? 30 : 70);
+		QVariant width = s.value(QString("colwidth%1").arg(i), defaultColumnWidth(i));
 		ui.tableView->setColumnWidth(i, width.toInt());
 	}
 	s.endGroup();
 
-	QFontMetrics metrics(defaultModelFont());
-	ui.tableView->horizontalHeader()->setMinimumHeight(metrics.height() + 10);
+	ui.tableView->horizontalHeader()->setMinimumHeight(metrics.header_ht);
 }
 
 void TableView::fixPlusPosition()
 {
-	plusBtn->setGeometry(ui.groupBox->contentsRect().width() - 30, 2, 24, 24);
+	int x = ui.groupBox->contentsRect().width() - 2*metrics.icon_size + metrics.btn_gap;
+	int y = metrics.btn_gap;
+	plusBtn->setGeometry(x, y, metrics.btn_size, metrics.btn_size);
 }
 
 // We need to manually position the 'plus' on cylinder and weight.
@@ -100,6 +118,11 @@ void TableView::edit(const QModelIndex &index)
 	ui.tableView->edit(index);
 }
 
+int TableView::defaultColumnWidth(int col)
+{
+	return col == CylindersModel::REMOVE ? metrics.rm_col_width : metrics.col_width;
+}
+
 QTableView *TableView::view()
 {
 	return ui.tableView;
diff --git a/qt-ui/tableview.h b/qt-ui/tableview.h
index d2289b2..00d7708 100644
--- a/qt-ui/tableview.h
+++ b/qt-ui/tableview.h
@@ -16,6 +16,15 @@ class QTableView;
 
 class TableView : public QWidget {
 	Q_OBJECT
+
+	struct TableMetrics {
+		int icon_size; // icon size
+		int btn_size; // button size
+		int btn_gap; // button gap
+		int col_width; // generic column width
+		int rm_col_width; // column width of REMOVE column
+		int header_ht; // height of the header
+	};
 public:
 	TableView(QWidget *parent = 0);
 	virtual ~TableView();
@@ -28,6 +37,7 @@ public:
 	void setBtnToolTip(const QString &tooltip);
 	void fixPlusPosition();
 	void edit(const QModelIndex &index);
+	int  defaultColumnWidth(int col); // default column width for column col
 	QTableView *view();
 
 protected:
@@ -40,6 +50,7 @@ signals:
 private:
 	Ui::TableView ui;
 	QPushButton *plusBtn;
+	TableMetrics metrics;
 };
 
 #endif // TABLEVIEW_H
-- 
2.1.0.255.gcd10c46