Method zValueAfterAddMoveRemove

tests/backend/Worksheet/WorksheetTest.cpp:121–178

! * tests the handling of z-values on changes in the child hierarchy. */

 * tests the handling of z-values on changes in the child hierarchy.
 */
void WorksheetTest::zValueAfterAddMoveRemove() {
	auto* worksheet = new Worksheet(QStringLiteral("Worksheet"));

	auto* plot1 = new CartesianPlot(QStringLiteral("plot1"));
	worksheet->addChild(plot1);

	auto* plot2 = new CartesianPlot(QStringLiteral("plot2"));
	worksheet->addChild(plot2);

	auto* plot3 = new CartesianPlot(QStringLiteral("plot3"));
	worksheet->addChild(plot3);

	// after the objects were added, the order of children is
	// * plot1
	// * plot2
	// * plot3
	int zValuePlot1 = plot1->graphicsItem()->zValue();
	int zValuePlot2 = plot2->graphicsItem()->zValue();
	int zValuePlot3 = plot3->graphicsItem()->zValue();
	QVERIFY(zValuePlot1 < zValuePlot2);
	QVERIFY(zValuePlot2 < zValuePlot3);

	// move plot2 up
	worksheet->moveChild(plot2, -1);

	// after the move, the order of children is
	// * plot2
	// * plot1
	// * plot3
	zValuePlot1 = plot1->graphicsItem()->zValue();
	zValuePlot2 = plot2->graphicsItem()->zValue();
	zValuePlot3 = plot3->graphicsItem()->zValue();
	QVERIFY(zValuePlot2 < zValuePlot1);
	QVERIFY(zValuePlot1 < zValuePlot3);

	// move plot1 down
	worksheet->moveChild(plot1, 1);

	// after the move, the order of children is
	// * plot2
	// * plot3
	// * plot1
	zValuePlot1 = plot1->graphicsItem()->zValue();
	zValuePlot2 = plot2->graphicsItem()->zValue();
	zValuePlot3 = plot3->graphicsItem()->zValue();
	QVERIFY(zValuePlot2 < zValuePlot3);
	QVERIFY(zValuePlot3 < zValuePlot1);

	// remove plot3
	worksheet->removeChild(plot3);

	// after the remove, the order of children is
	// * plot2
	// * plot1
	zValuePlot1 = plot1->graphicsItem()->zValue();
	zValuePlot2 = plot2->graphicsItem()->zValue();
	QVERIFY(zValuePlot2 < zValuePlot1);
}