public void ScrollToShowSelection()
{
ParaBox para;
RootBox root = ParaBuilderTests.MakeTestParaSimpleString(m_gm.VwGraphics, ParaBuilderTests.MockBreakOption.ThreeFullLines, out para);
PaintTransform ptrans = new PaintTransform(2, 4, 96, 96, 0, 0, 96, 96);
int dx, dy;
// If there is no selection we should not move.
root.ScrollToShowSelection(m_gm.VwGraphics, ptrans, new Rectangle(10, 10, 30, 50), out dx, out dy);
Assert.That(dx, Is.EqualTo(0));
Assert.That(dy, Is.EqualTo(0));
InsertionPoint ip = root.SelectAtEnd();
ip.Install();
// Take control of where the selection thinks it is.
var seg = ((StringBox)para.FirstBox).Segment as MockSegment;
seg.NextPosIpResult = new MockSegment.PositionsOfIpResults()
{
PrimaryHere = true, RectPrimary = new Rect(20, 30, 22, 40)
};
var rect = ip.GetSelectionLocation(m_gm.VwGraphics, ptrans);
Assert.That(rect.Top, Is.EqualTo(30));
Assert.That(rect.Bottom, Is.EqualTo(40));
// Todo JohnT: all current tests pass without horizontal scrolling. Eventually implement that.
// It's entirely inside the rectangle: don't scroll.
root.ScrollToShowSelection(m_gm.VwGraphics, ptrans, new Rectangle(10, 10, 30, 50), out dx, out dy);
Assert.That(dx, Is.EqualTo(0));
Assert.That(dy, Is.EqualTo(0));
// a special case of entirely inside: not by the desired margin: still don't scroll.
root.ScrollToShowSelection(m_gm.VwGraphics, ptrans, new Rectangle(10, 28, 30, 14), out dx, out dy);
Assert.That(dx, Is.EqualTo(0));
Assert.That(dy, Is.EqualTo(0));
// It's above a rectangle that can easily hold it: should end 10 pixels inside. Scrolling down 15 pixels will do that.
root.ScrollToShowSelection(m_gm.VwGraphics, ptrans, new Rectangle(10, 35, 30, 70), out dx, out dy);
Assert.That(dx, Is.EqualTo(0));
Assert.That(dy, Is.EqualTo(15));
// It's below a rectangle that can easily hold it: should end 10 pixels inside. Scrolling up 25 pixels will do that.
// (The bottom of the rectangle is at 25, 15 pix above the bottom of the selection rectangle.)
root.ScrollToShowSelection(m_gm.VwGraphics, ptrans, new Rectangle(10, -20, 30, 45), out dx, out dy);
Assert.That(dx, Is.EqualTo(0));
Assert.That(dy, Is.EqualTo(-25));
// It's above a rectangle that can not hold it comfortably: should end just inside. Scrolling down 5 pixels will do that.
root.ScrollToShowSelection(m_gm.VwGraphics, ptrans, new Rectangle(10, 35, 30, 20), out dx, out dy);
Assert.That(dx, Is.EqualTo(0));
Assert.That(dy, Is.EqualTo(5));
// It's below a rectangle that can not hold it comfortably: should end just inside. Scrolling up 15 pixels will do that.
// (The bottom of the rectangle is at 25, 15 pix above the bottom of the selection rectangle.)
root.ScrollToShowSelection(m_gm.VwGraphics, ptrans, new Rectangle(10, 0, 30, 25), out dx, out dy);
Assert.That(dx, Is.EqualTo(0));
Assert.That(dy, Is.EqualTo(-15));
// Pathologically, it may not be possible to display all of it at all. It's currently 12 pixels below the
// target rectangle. We move it so its top is one pixel above, that is, 12 plus 9 pixels.
root.ScrollToShowSelection(m_gm.VwGraphics, ptrans, new Rectangle(10, 10, 30, 8), out dx, out dy);
Assert.That(dx, Is.EqualTo(0));
Assert.That(dy, Is.EqualTo(-21));
// A similar case moving up. 10 pixels would align the tops; we move 2 less.
root.ScrollToShowSelection(m_gm.VwGraphics, ptrans, new Rectangle(10, 40, 30, 6), out dx, out dy);
Assert.That(dx, Is.EqualTo(0));
Assert.That(dy, Is.EqualTo(8));
// Todo JohnT: cases involving ranges. Mostly these work the same, when things fit. There are special cases
// when the range is not entirely visible, but its DragEnd is; also when the range doesn't entirely fit,
// but possibly its dragEnd does.
}