/// <summary>
/// Handles the movement of the mouse in the row header.
/// </summary>
/// <param name="e">The mouse movement event arguments.</param>
protected override void OnMouseMove(MouseEventArgs e)
{
// This gets the location of the mouse in document coordinates.
Point mouseLocation = e.GetPosition(this);
// The anchorRow describes the starting row for an extended selection. The selectedRow is the one over which
// the mouse is currently.
ReportRow selectedRow = this.ReportGrid.Rows.FindRowAt(mouseLocation.Y);
ReportRow anchorRow = this.ReportGrid.Rows.FindRowAt(this.anchorPoint.Y);
// The action taken by a mouse movement in the row heading of a viewer is driven by a set of states. These states
// are driven, in turn, by where the mouse started and what buttons are pressed. They can instruct the viewer to
// resize the rows, move the row, delete the row or sort the row.
switch (this.mouseState)
{
case MouseState.Selecting:
// When dragging the mouse around the row headings, the most recent range will be replaced. The new range consist
// of every row between the anchor row and the row over which the mouse is currently.
// HACK - Fix this when the selected range is guaranteed to have rows in it.
if (this.selectedRanges.Count > 0)
{
List <ReportRow> lastRange = this.selectedRanges[this.selectedRanges.Count - 1];
if ((lastRange[lastRange.Count - 1] != selectedRow) && (selectedRow != null))
{
// This will select each row between the last selected row and the one just selected. Note that the
// list of rows is distinct, so duplicate rows are ignored.
ReportRow firstRow = anchorRow.Top < selectedRow.Top ? anchorRow : selectedRow;
ReportRow secondRow = anchorRow.Top < selectedRow.Top ? selectedRow : anchorRow;
lastRange.Clear();
foreach (ReportRow reportRow in this.ReportGrid.Rows)
{
if (firstRow.Top <= reportRow.Top && reportRow.Top <= secondRow.Top)
{
lastRange.Add(reportRow);
}
}
// Add the row Header to the range also so the it will be highlight too.
lastRange.Add(ReportGrid.reportRowCollection.FindRowAt(0));
// This will select all the cells in the range of rows that have been selected. Everything else will be
// cleared. The active cell -- the one that has the input focus -- is the first cell of the anchor row.
SelectRows();
}
}
break;
case MouseState.ResizingRow:
// This will calculate the current row width based on the difference between the anchor point and the current mouse
// location.
double rowHeight = selectedRow.Height + (mouseLocation.Y - this.anchorPoint.Y);
// The owner of the header canvas is called to draw the row boundary line so that it follows the mouse when the
// user is resizing the rows. This operation can't be done from this canvas because the size of the scrolling
// canvas -- where the row boundary cursor line is displayed -- isn't known here.
if (this.ResizeMouseMove != null)
{
this.ResizeMouseMove(this, new ResizeRowEventArgs(selectedRow, rowHeight, false));
}
// As the size of the row is dragged around, the Popup widow displays a human readable form of the width.
this.rowHeightPopup.Content = rowHeight;
break;
case MouseState.ButtonDown:
// When the user presses the top mouse button, they initiate some drag operation and the mouse activity is
// captured by the row header window. If the user is simply moving the mouse over the window, then feedback is
// given in the shape of the cursor. This formula determins if the mouse has moved an absolute distance of four
// pixels from the original location. If it has, the user has selected a movement operation for the row.
// Otherwise, the mouse operation will be interpreted as a request for a new sort order when the top mouse button
// is lifted.
if (Math.Sqrt(Math.Pow(mouseLocation.Y - this.mouseDownLocation.Y, 2.0) +
Math.Pow(mouseLocation.Y - this.mouseDownLocation.Y, 2.0)) > DynamicReport.headerDragTrigger)
{
// At this point the mouse movements are intepreted as drag-and-drop operations for the row headers. The
// drop states determines what happens when the mouse button is released. It can either be moved, deleted or
// have no action taken.
this.mouseState = MouseState.DraggingRow;
this.destinationState = DropAction.NoAction;
// When dragging a row, the proposed destination appears as a set of two red arrows marking where the row
// will reside if dropped. The scale of the destination arrows must match the scale of the report.
this.destinationPopup.Scale = this.ReportGrid.DynamicReport.Scale;
this.destinationPopup.Visibility = Visibility.Hidden;
this.destinationPopup.IsOpen = true;
// This sets up the dragging operation by creating a destination cursor (the red arrows that point to where the
// row will 'snap' into place), a row cursor (it looks like the row header was ripped out of the page)
// and positions the row cursor at the tip of the current mouse location.
this.headerPopup.Resources = this.ReportGrid.Resources;
this.headerPopup.Content = this.headerCells;
this.headerPopup.Scale = this.ReportGrid.DynamicReport.Scale;
this.headerPopup.Height = selectedRow.Height;
this.headerPopup.Width = this.ActualWidth;
this.headerPopup.Location = mouseLocation;
this.headerPopup.IsOpen = true;
}
break;
case MouseState.DraggingRow:
// If the window that contains the row headings contains the cursor, then it's possible that a destination is
// selected for the row drag-and-drop operation. If the cursor is outside of the header quadrant, the row
// will be deleted when the mouse button is released.
if (this.Viewport.Contains(mouseLocation))
{
// Any operation inside the visible header gets the basic pointing arrow for a cursor.
this.Cursor = this.selectRow;
// When the mouse is inside the header quadrant but there is no destination selected, then nothing will happen
// when the mouse button is release.
this.destinationState = DropAction.NoAction;
// This attempts to find a destination for the row operation.
if (selectedRow != null)
{
// A row can't be its own destination.
if (anchorRow != selectedRow)
{
// A destination is selected if the left edge of the target column is entirely visible in the header
// quadrant and the left half of the column header contains the current mouse location.
Rect testAreaTop = new Rect(this.Viewport.Left, selectedRow.Top, this.Viewport.Width,
selectedRow.Height / 2.0);
if (testAreaTop.Contains(mouseLocation) && anchorRow.Bottom != selectedRow.Top)
{
this.destinationState = DropAction.Select;
this.destinationRow = selectedRow;
}
// This will test the right half of each of the colum headers. If the cursor is over the right half
// and the rightmost part of the destination is entirely visible in the header, then it can be a
// destination.
Rect testAreaBottom = new Rect(this.Viewport.Left, selectedRow.Top + selectedRow.Height / 2.0,
this.Viewport.Width, selectedRow.Height / 2.0);
if (testAreaBottom.Contains(mouseLocation) && selectedRow.Bottom != anchorRow.Top)
{
this.destinationState = DropAction.Select;
this.destinationRow = null;
foreach (ReportRow nextRow in this.ReportGrid.Rows)
{
if (nextRow.Top == selectedRow.Bottom)
{
this.destinationRow = nextRow;
}
}
}
}
}
// If a valid destination was found in the search above, move the set of red arrows (the destination cursor)
// over the exact spot where the row will be moved.
if (this.destinationState == DropAction.Select)
{
this.destinationPopup.VerticalOffset = this.destinationRow == null ?
this.ReportGrid.ExtentHeight : this.destinationRow.Top;
this.destinationPopup.Visibility = Visibility.Visible;
}
else
{
this.destinationPopup.Visibility = Visibility.Hidden;
}
}
else
{
// If the mouse isn't over the row header quadrant, a big 'X' instead of the destination cursor give the
// user feedback that the row will be dropped from the viewer if they release the mouse button.
this.destinationPopup.Visibility = Visibility.Hidden;
this.Cursor = this.bigEx;
// This will instruct the 'mouse up' action to delete the currently selected row.
this.destinationState = DropAction.Delete;
}
// The cursor row is really a floating window, not a cursor. It needs to be moved to match the location of the
// mouse. Note that the floating window doesn't have a parent, so the coordinates are in screen units.
this.headerPopup.Location = mouseLocation;
break;
case MouseState.ButtonUp:
// This will determine which cursor should be used when the button isn't pressed while moving the mouse: a horizontal
// size cursor or a regular arrow cursor. If the mouse is over the bottom or top edge of the row, then the
// horizontal resizing cursor is used.
bool isResizingRow = false;
// This will attempt to hit test the current row to see if it is a candidate for resizing.
if (selectedRow != null)
{
// This is a 'Hit Test' for the bottom edge of the row header tile to see if the user is trying to change the
// size of the row.
if (selectedRow.Top + selectedRow.Height - DynamicReport.splitBorder <= mouseLocation.Y &&
mouseLocation.Y < selectedRow.Top + selectedRow.Height)
{
isResizingRow = true;
}
// This is a 'Hit Test' for the top edge of the row header tile to see if the user is trying to change the
// size of the row.
if (selectedRow.Top <= mouseLocation.Y &&
mouseLocation.Y < selectedRow.Top + DynamicReport.splitBorder)
{
isResizingRow = true;
}
}
// Only the selection cursor is used when the header is frozen. When unfrozen, select the resizing cursor when
// the mouse is over the edge of the column header.
this.Cursor = this.IsHeaderFrozen || !isResizingRow ? this.selectRow : this.horizontalSplit;
break;
}
}
/// <summary>
/// Handles the mouse button being released over a row header.
/// </summary>
/// <param name="state">The thread initialization parameter.</param>
protected override void OnMouseUp(MouseButtonEventArgs e)
{
// This gets the location of the mouse in document coordinates.
Point mouseLocation = e.GetPosition(this);
// Evaluate the state of the keyboard. Key combinations involving the shift and control keys will alter the areas that
// are selected.
bool isShiftKeyPressed = ((Keyboard.Modifiers & ModifierKeys.Shift) == ModifierKeys.Shift);
bool isControlKeyPressed = ((Keyboard.Modifiers & ModifierKeys.Control) == ModifierKeys.Control);
// The target row for any movement operations is the last row selected.
ReportRow anchorRow = this.ReportGrid.Rows.FindRowAt(this.anchorPoint.Y);
// The mouse state indications what action should be taken when the mouse button is released.
switch (this.mouseState)
{
case MouseState.ResizingRow:
// At the conclusion of the resizing operation a decision is made to remove or change the width of a row. If
// the size is reduced to zero (or less), this gesture is taken as a command to remove the row. Any positive
// value for a width will result in a row change command.
double rowHeight = anchorRow.Height + (mouseLocation.Y - this.anchorPoint.Y);
rowHeight = rowHeight < 0.0 ? 0.0 : rowHeight;
if (this.ResizeMouseMove != null)
{
this.ResizeMouseMove(this, new ResizeRowEventArgs(anchorRow, rowHeight, true));
}
// Note - this is where the logic should go for removing or resizing a row. It should probably bubble up through
// the Report and be handled by some higher logic that determins if removing or resizing a row is a legal action.
// Currently it is not supported.
// This will hide the popup until it is needed again.
this.rowHeightPopup.IsOpen = false;
// This is a momentary button: the column heading will loose the selection state when the button is released.
foreach (ReportCell reportCell in this.headerCells)
{
reportCell.IsSelected = false;
}
break;
case MouseState.DraggingRow:
// The action taken when the dragging operation is complete depends on whether a valid destination is selected or
// whether the row is meant to be deleted.
switch (this.destinationState)
{
case DropAction.Select:
// This will move the row from its current location to the desired location.
if (this.destinationPopup.Visibility == Visibility.Visible)
{
// TODO - This should generate an event to move a row from one place to another.
}
break;
case DropAction.Delete:
// This will delete the row from the view.
this.ReportGrid.Rows.Remove(anchorRow);
break;
}
// This is a momentary button: the column heading will loose the selection state when the button is released.
foreach (ReportCell reportCell in this.headerCells)
{
reportCell.IsSelected = false;
}
break;
}
// This resets the state of the mouse for the next operation.
this.mouseState = MouseState.ButtonUp;
if (this.headerPopup.IsOpen)
{
this.headerPopup.IsOpen = false;
}
// Hide the destination cursor when the mouse is released.
if (this.destinationPopup.IsOpen)
{
this.destinationPopup.IsOpen = false;
}
// Release the Hounds, errr... mouse.
Mouse.Capture(null);
}
/// <summary>
/// Handles the mouse button being pressed.
/// </summary>
/// <param name="e">The event arguments.</param>
protected override void OnMouseDown(System.Windows.Input.MouseButtonEventArgs e)
{
// The sort order is maintained in this structure.
this.sortOrder = new List <SortItem>();
// This gets the location of the mouse in document coordinates.
Mouse.Capture(this);
// This state variable will control how the 'Mouse Move' and 'Mouse Up' event handlers interpret the user action. The
// 'selectedRow' field is used as the starting point for any drag-and-drop type of operation.
this.mouseState = MouseState.ButtonDown;
// Evaluate the state of the keyboard. Key combinations involving the shift and control keys will alter the areas that
// are selected.
bool isShiftKeyPressed = ((Keyboard.Modifiers & ModifierKeys.Shift) == ModifierKeys.Shift);
bool isControlKeyPressed = ((Keyboard.Modifiers & ModifierKeys.Control) == ModifierKeys.Control);
// This will use the current position for an anchor unless the shift key is pressed.
this.mouseDownLocation = e.GetPosition(this);
if (!isShiftKeyPressed)
{
this.anchorPoint = this.mouseDownLocation;
}
// The mouse indicates which column has been selected and the anchor indicates the starting point of the selection in
// an extended selection operation.
ReportRow selectedRow = this.ReportGrid.Rows.FindRowAt(this.mouseDownLocation.Y);
ReportRow anchorRow = this.ReportGrid.Rows.FindRowAt(this.anchorPoint.Y);
Point mouseDownLocation = e.GetPosition(this);
if (!isShiftKeyPressed)
{
IInputElement iInputElement = this.InputHitTest(mouseDownLocation);
DependencyObject dependencyObject = iInputElement as DependencyObject;
while (dependencyObject != null)
{
if (DynamicReport.GetCell(dependencyObject) != null)
{
Keyboard.Focus(dependencyObject as IInputElement);
break;
}
dependencyObject = VisualTreeHelper.GetParent(dependencyObject);
}
}
// Every cell that appears in the header canvas is considered part of the selectable header. This will collect all the
// selected cells in a list while creating a rectangle that is the union of all those selected cells.
this.headerCells.Clear();
foreach (ReportColumn reportColumn in this.ReportGrid.Columns)
{
ReportCell reportCell = selectedRow[reportColumn];
if (reportColumn.Left < this.ActualWidth)
{
this.headerCells.Add(reportCell);
}
}
// If a row is selected then the position and movement of the mouse will suggest one of several gestures that need
// to be interpreted: is a row being moved, is it being resized, is it being deleted or selected? The code below
// will begin to interpret the input gesture.
if (selectedRow != null)
{
// The header has two modes: when the headers are frozen, only selection operations are enabled with the mouse.
// When not frozen, the rows can be moved, resized, resorted and removed.
if (this.IsHeaderFrozen)
{
// The shift and control key extend the selection operation in the same way as Microsoft Excel.
if (isShiftKeyPressed || isControlKeyPressed)
{
// When the shift key is pressed during row selection, every row between the last row selected
// and the current row is selected.
if (isShiftKeyPressed)
{
// In the unlikely event that the shift key was down during the setting of the anchor point, this will
// create a dummy entry in the list of selected row ranges.
if (this.selectedRanges.Count == 0)
{
List <ReportRow> reportRows = new List <ReportRow>();
reportRows.Add(selectedRow);
this.selectedRanges.Add(reportRows);
}
// The most recent range will be replaced with a new range when the mouse is dragged around the row
// headers. This has the effect of clearing the rows that are no longer selected and selecting only
// the rows between the anchor and the currently selected row.
List <ReportRow> lastRange = this.selectedRanges[this.selectedRanges.Count - 1];
// This will select each row between the last selected row and the one just selected. Note that the
// list of rows is distinct, so duplicate rows are ignored.
ReportRow firstRow = anchorRow.Top < selectedRow.Top ? anchorRow : selectedRow;
ReportRow secondRow = anchorRow.Top < selectedRow.Top ? selectedRow : anchorRow;
lastRange.Clear();
foreach (ReportRow reportRow in this.ReportGrid.Rows)
{
if (firstRow.Top <= reportRow.Top && reportRow.Top <= secondRow.Top)
{
lastRange.Add(reportRow);
}
}
}
// When the control key is pressed a single row is added to the range of rows selected.
if (isControlKeyPressed)
{
// This removes any previous instance of this row in the selection.
foreach (List <ReportRow> rowRange in this.selectedRanges)
{
if (rowRange.Contains(selectedRow))
{
rowRange.Remove(selectedRow);
}
}
// The row is added (or re-added) at the start of the range of selected rows.
List <ReportRow> reportRows = new List <ReportRow>();
reportRows.Add(selectedRow);
this.selectedRanges.Add(reportRows);
}
}
else
{
// The row is added at the start of a new range of selected rows.
List <ReportRow> reportRows = new List <ReportRow>();
// The if condition below fixes issue that allows the right click to not clear the selected rows.
// Hence it allows every other condition to clear the state.
if (e.RightButton != MouseButtonState.Pressed)
{
// A simple selection that doesn't involve the modifier keys will clear out any previously selected ranges.
this.selectedRanges.Clear();
}
else
{
// This removes any previous instance of this row in the selection.
foreach (List <ReportRow> rowRange in this.selectedRanges)
{
if (rowRange.Contains(selectedRow))
{
rowRange.Remove(selectedRow);
}
}
}
reportRows.Add(selectedRow);
this.selectedRanges.Add(reportRows);
}
// This will select all the rows in the selected ranges of rows and remove the selection from all the
// rest of the cells.
SelectRows();
// This instructs the event handlers how the mouse movement is to be interpreted.
this.mouseState = MouseState.Selecting;
}
else
{
// The top mouse button can either select the row or begin a resizing operation. This will perform a 'Hit
// Test' to see which operation should be performed.
if (e.LeftButton == MouseButtonState.Pressed)
{
// This is a 'Hit Test' for the bottom edge of the row header tile to see if the user is trying to change
// the size of the row. If the mouse is close to the bottom edge, then the drag operation to change the
// size of the tile is begun.
if (selectedRow.Bottom - DynamicReport.splitBorder <= this.mouseDownLocation.Y &&
this.mouseDownLocation.Y < selectedRow.Bottom)
{
this.resizeStart = selectedRow.Bottom;
this.mouseState = MouseState.ResizingRow;
this.destinationRow = null;
}
else
{
// This is a 'Hit Test' for the top edge of the row header tile to see if the user is trying to change
// the size of the row. Note that because the top edge really belongs to the previous row header when
// resizing, that the previous row is selected for the operation.
if (selectedRow.Top <= this.mouseDownLocation.Y &&
this.mouseDownLocation.Y < selectedRow.Top + DynamicReport.splitBorder)
{
this.resizeStart = selectedRow.Top;
this.mouseState = MouseState.ResizingRow;
foreach (ReportRow reportRow in this.ReportGrid.Rows)
{
if (reportRow.Bottom == selectedRow.Top)
{
selectedRow = reportRow;
}
}
this.destinationRow = null;
}
}
}
// At this point, a resizing operation has been selected from the input gesture of the mouse.
if (this.mouseState == MouseState.ResizingRow)
{
// The parent window will watch for this event to tell it how to draw the row width indicator lines. The
// dimension and location of those lines are outside of this window and must be handled by the parent.
if (this.ResizeMouseMove != null)
{
this.ResizeMouseMove(this, new ResizeRowEventArgs(selectedRow, selectedRow.Height,
false));
}
// This window provides quantitative feedback for the new width of the row. The offsets were arrived at
// empirically from reverse engineering Excel.
this.rowHeightPopup.VerticalOffset = this.mouseDownLocation.Y - 2.0;
this.rowHeightPopup.Content = selectedRow.Height;
this.rowHeightPopup.IsOpen = true;
}
else
{
// This will select the button momentarily for drag-and-drop and sorting operations.
foreach (ReportCell reportCell in this.headerCells)
{
reportCell.IsSelected = true;
}
}
}
}
}
