ImageGear22.Core Assembly > ImageGear.Display Namespace > IImGearPageDisplay Interface : ZoomToRectangle Method |
'Declaration Sub ZoomToRectangle( _ ByVal pageView As IImGearScrollableView, _ ByVal rect As ImGearRectangle _ )
'Usage Dim instance As IImGearPageDisplay Dim pageView As IImGearScrollableView Dim rect As ImGearRectangle instance.ZoomToRectangle(pageView, rect)
void ZoomToRectangle( IImGearScrollableView pageView, ImGearRectangle rect )
void ZoomToRectangle( IImGearScrollableView* pageView, ImGearRectangle rect )
void ZoomToRectangle( IImGearScrollableView^ pageView, ImGearRectangle rect )
ImGearZoomComponentInfo
.Fixed
field to true, calculates and modifies ImGearZoomComponentInfo
.Value
field, the horizontal and vertical scroll positions, and returns new instance of ImGearZoomInfo
object with new zoom attributes.// Variable to toggle if user is currently selecting an area. private bool m_bZoomToRectSelect = false; // Set of points defining the selected area. private ImGearPoint[] igPointsZoomToRect; // Color of selection box. private Color m_SelectorColor = Color.White; // Method to return appropriate height for a specific width // based upon the size of a scrollable view. private int GetHeight(IImGearScrollableView igScrollableView, int Width) { return Width * igScrollableView.ClientRectangle.Height / igScrollableView.ClientRectangle.Width; } private void menuZoomToRect_Click(object sender, EventArgs e) { // Menu item used to toggle if Zoom to Rectangle is on or not. menuZoomToRect.Checked = !menuZoomToRect.Checked; } private void imGearPageView1_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e) { if (menuZoomToRect.Checked) { // Enter Zoom to Rectangle selection mode. m_bZoomToRectSelect = true; // Create a new pair of points to define the rectangle, // setting the first point to the current position. igPointsZoomToRect = new ImGearPoint[2]; igPointsZoomToRect[0].X = e.X; igPointsZoomToRect[0].Y = e.Y; // Register method to draw the selection rectangle. imGearPageView.RegisterAfterDraw( new ImGearPageView.AfterDraw(DrawSelector)); } } private void imGearPageView1_MouseUp(object sender, System.Windows.Forms.MouseEventArgs e) { if (m_bZoomToRectSelect) { // Leave Zoom to Rectangle selection mode. imGearPageView.RegisterAfterDraw(null); m_bZoomToRectSelect = false; // Record the second point of the zoom rectangle, // normalizing it to the view's aspect ratio. igPointsZoomToRect[1].X = e.X; igPointsZoomToRect[1].Y = igPointsZoomToRect[0].Y + GetHeight(imGearPageView, Math.Abs(igPointsZoomToRect[1].X - igPointsZoomToRect[0].X) + 1) - 1; // Create a rectangle based upon the 2 points. ImGearRectangle igRectangle = new ImGearRectangle(igPointsZoomToRect[0], igPointsZoomToRect[1]); // Cancel the zoom if it would be for a 0x0 or 1x1 rectangle. if (igRectangle.Width <= 1 || igRectangle.Height <= 1) return; // Zoom to the selected rectangle imGearPageView.Display.ZoomToRectangle(imGearPageView, igRectangle); imGearPageView.Invalidate(); // Disable Zoom to Rectangle. menuZoomToRect.Checked = false; } } private void imGearPageView1_MouseMove(object sender, System.Windows.Forms.MouseEventArgs e) { if (m_bZoomToRectSelect) { // Record the second point of the zoom rectangle, // normalizing it to the view's aspect ratio. igPointsZoomToRect[1].X = e.X; igPointsZoomToRect[1].Y = igPointsZoomToRect[0].Y + GetHeight(imGearPageView, Math.Abs(igPointsZoomToRect[1].X - igPointsZoomToRect[0].X) + 1) - 1; // Cause a redraw which will update the zoom selection rectangle. imGearPageView.Invalidate(); } } private void DrawSelector(System.Drawing.Graphics gr) { if (m_bZoomToRectSelect) { // Create a new pen to draw dotted lines. Pen pen = new Pen(m_SelectorColor); pen.DashStyle = DashStyle.Dot; // Define the currently selected zoom rectangle. ImGearRectangle igRectangleZoom = new ImGearRectangle(igPointsZoomToRect[0], igPointsZoomToRect[1]); // Draw the selection box. gr.DrawRectangle(pen, igRectangleZoom.Left, igRectangleZoom.Top, igRectangleZoom.Width, igRectangleZoom.Height); } }
'Variable to toggle if user is currently selecting an area. Private m_bZoomToRectSelect As Boolean = False 'Set of points defining the selected area. Private igPointsZoomToRect() As ImGearPoint 'Color of selection box. Private m_SelectorColor As Color = Color.White 'Function to return appropriate height for a specific width ' based upon the size of a scrollable view. Private Function GetHeight(ByVal igScrollableView As IImGearScrollableView, ByVal Width As Integer) As Integer GetHeight = Width * igScrollableView.ClientRectangle.Height / igScrollableView.ClientRectangle.Width End Function Private Sub menuZoomtoRect_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) _ Handles menuZoomtoRect.Click menuZoomtoRect.Checked = Not menuZoomtoRect.Checked End Sub Private Sub ImGearPageView1_MouseDown(ByVal sender As System.Object, ByVal e As System.Windows.Forms.MouseEventArgs) _ Handles ImGearPageView1.MouseDown If (menuZoomtoRect.Checked) Then 'Enter Zoom to Rectangle selection mode. m_bZoomToRectSelect = True 'Create a new pair of points to define the rectangle, ' setting the first point to the current position. ReDim igPointsZoomToRect(2) igPointsZoomToRect(0).X = e.X igPointsZoomToRect(0).Y = e.Y 'Register function to draw the selection rectangle. ImGearPageView1.RegisterAfterDraw( _ New ImGearPageView.AfterDraw(AddressOf DrawSelector)) End If End Sub Private Sub ImGearPageView1_MouseUp(ByVal sender As System.Object, ByVal e As System.Windows.Forms.MouseEventArgs) _ Handles ImGearPageView1.MouseUp If (m_bZoomToRectSelect) Then 'Leave Zoom to Rectangle selection mode. ImGearPageView1.RegisterAfterDraw(Nothing) m_bZoomToRectSelect = False 'Record the second point of the zoom rectangle, ' normalizing it to the view's aspect ratio. igPointsZoomToRect(1).X = e.X igPointsZoomToRect(1).Y = igPointsZoomToRect(0).Y + _ GetHeight(ImGearPageView1, Math.Abs(igPointsZoomToRect(1).X - igPointsZoomToRect(0).X) + 1) - 1 'Create a rectangle based upon the 2 points. Dim igRectangle As ImGearRectangle = New ImGearRectangle(igPointsZoomToRect(0), igPointsZoomToRect(1)) 'Cancel the zoom if it would be for a 0x0 or 1x1 rectangle. If (igRectangle.Width <= 1 Or igRectangle.Height <= 1) Then Return End If 'Zoom to the selected rectangle ImGearPageView1.Display.ZoomToRectangle(ImGearPageView1, igRectangle) ImGearPageView1.Invalidate() 'Disable Zoom to Rectangle. menuZoomtoRect.Checked = False End If End Sub Private Sub ImGearPageView1_MouseMove(ByVal sender As System.Object, ByVal e As System.Windows.Forms.MouseEventArgs) _ Handles ImGearPageView1.MouseMove If (m_bZoomToRectSelect) Then 'Record the second point of the zoom rectangle, ' normalizing it to the view's aspect ratio. igPointsZoomToRect(1).X = e.X igPointsZoomToRect(1).Y = igPointsZoomToRect(0).Y + _ GetHeight(ImGearPageView1, Math.Abs(igPointsZoomToRect(1).X - igPointsZoomToRect(0).X) + 1) - 1 'Cause a redraw which will update the zoom selection rectangle. ImGearPageView1.Invalidate() End If End Sub Private Sub DrawSelector(ByVal gr As System.Drawing.Graphics) If (m_bZoomToRectSelect) Then 'Create a new pen to draw dotted lines. Dim pen As Pen = New Pen(m_SelectorColor) Pen.DashStyle = DashStyle.Dot 'Define the currently selected zoom rectangle. Dim igRectangleZoom As ImGearRectangle = New ImGearRectangle(igPointsZoomToRect(0), igPointsZoomToRect(1)) 'Draw the selection box. gr.DrawRectangle(pen, igRectangleZoom.Left, igRectangleZoom.Top, igRectangleZoom.Width, igRectangleZoom.Height) End If End Sub