C# Класс SIL.FieldWorks.SharpViews.RootBox

Checks whether the Selection can be deleted

Since this IS the root, by definition the root transform is its transform.

Call this ever half second or so to make the insertion point (if any) flash.

Changes the style of the Selection to the chosen style

If the Selection is an Insertion Point the character following the Selection will be removed If the Selection is a Ranged Selection the entire Selection will be removed

Implement dragging to this view.

Returns information about possible drops with these arguments.

Called when drag leaves this control.

Places an insertion point within a ranged selection, only if the mouse down occured within the selection. OnMouseDown takes care of all other situations.

Places an insertion point unless it would be placed within a ranged selection. Also determines sets whether the mouse down occured within a ranged selection, so that OnMouseMove can know if it can drag and so that OnMouseClick can know if can place an insertion point within the ranged selection.

Allows for text to be selected and dragged. This method starts the drag instead of OnMouseDown because once the drag is started, OnMouseClick/DoubleClick is overridden. OnMouseDown would start the drag too early.

Despite the method name (chosen to match the method of Control which it implements), our main reason for implementing this is to be notified when the drop takes place and, if it is a move, delete the original.

The root box handles the overall paint.

Determine how far we need to scroll to make the current selection visible within the target rectangle (typically the clientRect of the view). Currently the goal is - if the selection is entirely within the rectangle return 0,0 (don't move) - otherwise if possible move the smallest distance that will put the selection at least 10 pixels inside the rectangle on both sides - if that is not possible move the smallest distance that will put the selection entirely inside the rectangle - if that is not possible move so that the primary rectangle of the IP at the DragEnd of the selection is inside the rectangle, at the top if it is the start and at the bottom if it is at the end. - if it is not possible to display even the primary rectangle of one IP, move so that equal amounts of it are above and below the rectangle. Eventually when we do horizontal scrolling the two directions will be independent. For example, even if we must move vertically, don't move horizontally to get the 10 pixel margin unless we must to see it at all.

Checks whether a Selection's style can be changed

This is basically the common logic of MouseDown and MouseMove, when the left mouse button is pressed. If makeRange is true, as for shift-click or mouse move, we try to move the drag end of a range; otherwise, we make the selection where it is.

Answer a viewbuilder for adding stuff to the specified box. Subclasses may wish to return a subclass of ViewBuilder.

Overriden since, if our old Height is zero, the base method will assume the box is new and does not need invalidate, since it's container will figure its new area. But the root has no container, so we handle this special case here.