// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF
// ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO
// THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A
// PARTICULAR PURPOSE.
//
// Copyright (c) Microsoft Corporation. All rights reserved.
//
// File: InkCollection.cs
// Simple Ink Collection Sample Application
//
// This sample program demonstrates how to zoom and scroll
// ink. In particular, it allows the user to zoom in and out
// of ink in increments. It also demonstrates how to zoom
// into a particular region using a zoom rectangle. Finally,
// this sample illustrates that ink can be collected at different
// zoom levels and how to set up scrolling within the zoomed
// drawing area.
//
// In the code below, Renderer's view and object transforms are
// used to perform zooming and scrolling. The view transform
// applies to the points and the pen width. The object transform
// applies only to the points. The user can control which transform
// is used by changing the Mode->Scale Pen Width menu setting of
// this sample.
//
// The features used are: InkCollector, Renderer.SetViewTransform(),
// and Renderer.SetObjectTransform().
//
//--------------------------------------------------------------------------
using System;
using System.Drawing;
using System.Windows.Forms;
using System.Drawing.Drawing2D;
// The Ink namespace, which contains the Tablet PC Platform API
using Microsoft.Ink;
namespace Microsoft.Samples.TabletPC.InkZoom
{
///
/// The InkZoom Sample Application form class
///
public class InkZoom : System.Windows.Forms.Form
{
// Declare the Ink Collector object
private InkCollector myInkCollector = null;
// The pen used for drawing the zoom rectangle
Pen blackPen = null;
// The zoom rectangle
private Rectangle zoomRectangle = Rectangle.Empty;
// The current zoom factor (1 = 100% zoom level)
private float zoomFactor = 1;
// Declare constants for the width and height of the
// drawing area (in ink space coordinates).
private const int InkSpaceWidth = 50000;
private const int InkSpaceHeight = 50000;
// Declare constant for the size of the desired small change
private const int SmallChangeSize = 2;
// Declare constant for the pen width used by this application
private const float MediumInkWidth = 100;
#region Standard Template Code
private System.Windows.Forms.HScrollBar hScrollBar;
private System.Windows.Forms.VScrollBar vScrollBar;
private System.Windows.Forms.MenuItem miOther;
private System.Windows.Forms.MenuItem miZoomToRect;
private System.Windows.Forms.Panel pnlDrawingArea;
private System.Windows.Forms.MenuItem miFile;
private System.Windows.Forms.MenuItem miExit;
private System.Windows.Forms.Label lblZoom;
private System.Windows.Forms.NumericUpDown zoomUpDown;
private System.Windows.Forms.Panel pnlZoom;
private System.Windows.Forms.MenuItem miScalePenWidth;
private System.Windows.Forms.MenuItem miInk;
private System.Windows.Forms.MainMenu miMain;
private System.Windows.Forms.MenuItem miActionSeparator;
private System.Windows.Forms.MenuItem miModeSepararator;
private System.Windows.Forms.MenuItem miClear;
private System.Windows.Forms.ToolBar zoomToolBar;
private System.ComponentModel.Container components = null;
#endregion
///
/// The InkZoom Sample Application form class
///
public InkZoom()
{
#region Standard Template Code
//
// Required for Windows Form Designer support
//
InitializeComponent();
#endregion
}
#region Standard Template Code
///
/// Clean up any resources being used.
///
protected override void Dispose( bool disposing )
{
if( disposing )
{
if (components != null)
{
components.Dispose();
}
if (myInkCollector != null)
{
myInkCollector.Dispose();
}
}
base.Dispose( disposing );
}
#endregion
#region Windows Form Designer generated code
///
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
///
private void InitializeComponent()
{
this.hScrollBar = new System.Windows.Forms.HScrollBar();
this.vScrollBar = new System.Windows.Forms.VScrollBar();
this.miMain = new System.Windows.Forms.MainMenu();
this.miFile = new System.Windows.Forms.MenuItem();
this.miClear = new System.Windows.Forms.MenuItem();
this.miActionSeparator = new System.Windows.Forms.MenuItem();
this.miExit = new System.Windows.Forms.MenuItem();
this.miOther = new System.Windows.Forms.MenuItem();
this.miInk = new System.Windows.Forms.MenuItem();
this.miZoomToRect = new System.Windows.Forms.MenuItem();
this.miModeSepararator = new System.Windows.Forms.MenuItem();
this.miScalePenWidth = new System.Windows.Forms.MenuItem();
this.pnlZoom = new System.Windows.Forms.Panel();
this.lblZoom = new System.Windows.Forms.Label();
this.zoomUpDown = new System.Windows.Forms.NumericUpDown();
this.zoomToolBar = new System.Windows.Forms.ToolBar();
this.pnlDrawingArea = new System.Windows.Forms.Panel();
this.pnlZoom.SuspendLayout();
((System.ComponentModel.ISupportInitialize)(this.zoomUpDown)).BeginInit();
this.SuspendLayout();
//
// hScrollBar
//
this.hScrollBar.Anchor = ((System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Left)
| System.Windows.Forms.AnchorStyles.Right);
this.hScrollBar.LargeChange = 100;
this.hScrollBar.Location = new System.Drawing.Point(0, 279);
this.hScrollBar.Maximum = 1000;
this.hScrollBar.Name = "hScrollBar";
this.hScrollBar.Size = new System.Drawing.Size(275, 17);
this.hScrollBar.TabIndex = 0;
this.hScrollBar.ValueChanged += new System.EventHandler(this.hScrollBar_ValueChanged);
this.hScrollBar.Scroll += new System.Windows.Forms.ScrollEventHandler(this.hScrollBar_Scroll);
//
// vScrollBar
//
this.vScrollBar.Anchor = ((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom)
| System.Windows.Forms.AnchorStyles.Right);
this.vScrollBar.LargeChange = 100;
this.vScrollBar.Location = new System.Drawing.Point(275, 26);
this.vScrollBar.Maximum = 1000;
this.vScrollBar.Name = "vScrollBar";
this.vScrollBar.Size = new System.Drawing.Size(17, 254);
this.vScrollBar.TabIndex = 1;
this.vScrollBar.ValueChanged += new System.EventHandler(this.vScrollBar_ValueChanged);
this.vScrollBar.Scroll += new System.Windows.Forms.ScrollEventHandler(this.vScrollBar_Scroll);
//
// miMain
//
this.miMain.MenuItems.AddRange(new System.Windows.Forms.MenuItem[] {
this.miFile,
this.miOther});
//
// miFile
//
this.miFile.Index = 0;
this.miFile.MenuItems.AddRange(new System.Windows.Forms.MenuItem[] {
this.miClear,
this.miActionSeparator,
this.miExit});
this.miFile.Text = "&Action";
//
// miClear
//
this.miClear.Index = 0;
this.miClear.Text = "&Clear";
this.miClear.Click += new System.EventHandler(this.miClear_Click);
//
// miActionSeparator
//
this.miActionSeparator.Index = 1;
this.miActionSeparator.Text = "-";
//
// miExit
//
this.miExit.Index = 2;
this.miExit.Text = "E&xit";
this.miExit.Click += new System.EventHandler(this.miExit_Click);
//
// miOther
//
this.miOther.Index = 1;
this.miOther.MenuItems.AddRange(new System.Windows.Forms.MenuItem[] {
this.miInk,
this.miZoomToRect,
this.miModeSepararator,
this.miScalePenWidth});
this.miOther.Text = "&Mode";
//
// miInk
//
this.miInk.Checked = true;
this.miInk.Index = 0;
this.miInk.RadioCheck = true;
this.miInk.Text = "&Ink";
this.miInk.Click += new System.EventHandler(this.miInk_Click);
//
// miZoomToRect
//
this.miZoomToRect.Index = 1;
this.miZoomToRect.RadioCheck = true;
this.miZoomToRect.Text = "&Zoom To Rect";
this.miZoomToRect.Click += new System.EventHandler(this.miZoomToRect_Click);
//
// miModeSepararator
//
this.miModeSepararator.Index = 2;
this.miModeSepararator.Text = "-";
//
// miScalePenWidth
//
this.miScalePenWidth.Checked = true;
this.miScalePenWidth.Index = 3;
this.miScalePenWidth.Text = "&Scale Pen Width";
this.miScalePenWidth.Click += new System.EventHandler(this.miScalePenWidth_Click);
//
// pnlZoom
//
this.pnlZoom.Anchor = ((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Left)
| System.Windows.Forms.AnchorStyles.Right);
this.pnlZoom.BackColor = System.Drawing.SystemColors.Control;
this.pnlZoom.Controls.AddRange(new System.Windows.Forms.Control[] {
this.lblZoom,
this.zoomUpDown,
this.zoomToolBar});
this.pnlZoom.ForeColor = System.Drawing.SystemColors.ControlText;
this.pnlZoom.Name = "pnlZoom";
this.pnlZoom.Size = new System.Drawing.Size(292, 26);
this.pnlZoom.TabIndex = 3;
//
// lblZoom
//
this.lblZoom.Location = new System.Drawing.Point(8, 7);
this.lblZoom.Name = "lblZoom";
this.lblZoom.Size = new System.Drawing.Size(56, 16);
this.lblZoom.TabIndex = 3;
this.lblZoom.Text = "Zoom %:";
//
// zoomUpDown
//
this.zoomUpDown.Location = new System.Drawing.Point(64, 3);
this.zoomUpDown.Maximum = new System.Decimal(new int[] {
5000,
0,
0,
0});
this.zoomUpDown.Minimum = new System.Decimal(new int[] {
10,
0,
0,
0});
this.zoomUpDown.Name = "zoomUpDown";
this.zoomUpDown.Size = new System.Drawing.Size(56, 20);
this.zoomUpDown.TabIndex = 2;
this.zoomUpDown.Value = new System.Decimal(new int[] {
100,
0,
0,
0});
this.zoomUpDown.ValueChanged += new System.EventHandler(this.xZoomUpDown_ValueChanged);
//
// zoomToolBar
//
this.zoomToolBar.DropDownArrows = true;
this.zoomToolBar.Name = "zoomToolBar";
this.zoomToolBar.ShowToolTips = true;
this.zoomToolBar.Size = new System.Drawing.Size(292, 39);
this.zoomToolBar.TabIndex = 4;
//
// pnlDrawingArea
//
this.pnlDrawingArea.Anchor = (((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom)
| System.Windows.Forms.AnchorStyles.Left)
| System.Windows.Forms.AnchorStyles.Right);
this.pnlDrawingArea.BackColor = System.Drawing.Color.White;
this.pnlDrawingArea.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D;
this.pnlDrawingArea.Location = new System.Drawing.Point(0, 26);
this.pnlDrawingArea.Name = "pnlDrawingArea";
this.pnlDrawingArea.Size = new System.Drawing.Size(275, 254);
this.pnlDrawingArea.TabIndex = 4;
this.pnlDrawingArea.MouseUp += new System.Windows.Forms.MouseEventHandler(this.pnlDrawingArea_MouseUp);
this.pnlDrawingArea.MouseMove += new System.Windows.Forms.MouseEventHandler(this.pnlDrawingArea_MouseMove);
this.pnlDrawingArea.MouseDown += new System.Windows.Forms.MouseEventHandler(this.pnlDrawingArea_MouseDown);
//
// InkZoom
//
this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
this.ClientSize = new System.Drawing.Size(292, 296);
this.Controls.AddRange(new System.Windows.Forms.Control[] {
this.pnlDrawingArea,
this.pnlZoom,
this.vScrollBar,
this.hScrollBar});
this.Menu = this.miMain;
this.Name = "InkZoom";
this.Text = "InkZoom";
this.Resize += new System.EventHandler(this.InkZoom_Resize);
this.MouseDown += new System.Windows.Forms.MouseEventHandler(this.pnlDrawingArea_MouseDown);
this.Load += new System.EventHandler(this.InkZoom_Load);
this.MouseUp += new System.Windows.Forms.MouseEventHandler(this.pnlDrawingArea_MouseUp);
this.MouseMove += new System.Windows.Forms.MouseEventHandler(this.pnlDrawingArea_MouseMove);
this.pnlZoom.ResumeLayout(false);
((System.ComponentModel.ISupportInitialize)(this.zoomUpDown)).EndInit();
this.ResumeLayout(false);
}
#endregion
#region Standard Template Code
///
/// The main entry point for the application.
///
[STAThread]
static void Main()
{
Application.Run(new InkZoom());
}
#endregion
///
/// Event Handle from form Load Event
///
/// The control that raised the event.
/// The event arguments.
private void InkZoom_Load(object sender, System.EventArgs e)
{
// Create the pen used to draw the zoom rectangle
blackPen = new Pen(Color.Black, 1);
// Create the ink collector and associate it with the form
myInkCollector = new InkCollector(pnlDrawingArea.Handle);
// Set the pen width
myInkCollector.DefaultDrawingAttributes.Width = MediumInkWidth;
// Enable ink collection
myInkCollector.Enabled = true;
// Define ink space size - note that the scroll bars
// map directly to ink space
hScrollBar.Minimum = 0;
hScrollBar.Maximum = InkSpaceWidth;
vScrollBar.Minimum = 0;
vScrollBar.Maximum = InkSpaceHeight;
// Set the scroll bars to map to the current zoom level
UpdateZoomAndScroll();
}
///
/// Event Handle from xZoomUpDown Click Event
///
/// The control that raised the event.
/// The event arguments.
private void xZoomUpDown_ValueChanged(object sender, System.EventArgs e)
{
// Update the zoom factor to the new value
zoomFactor = (float)zoomUpDown.Value/100;
// Apply the new zoom/scroll settings
UpdateZoomAndScroll();
}
///
/// Event Handle from Horizontal Scroll Event
///
/// The control that raised the event.
/// The event arguments.
private void hScrollBar_Scroll(object sender, System.Windows.Forms.ScrollEventArgs e)
{
// Apply the new zoom/scroll settings
UpdateZoomAndScroll();
}
///
/// Event Handle from Vertical Scroll Event
///
/// The control that raised the event.
/// The event arguments.
private void vScrollBar_Scroll(object sender, System.Windows.Forms.ScrollEventArgs e)
{
// Apply the new zoom/scroll settings
UpdateZoomAndScroll();
}
///
/// Event Handle from Horizontal Scroll Value Changed Event
///
/// The control that raised the event.
/// The event arguments.
private void hScrollBar_ValueChanged(object sender, System.EventArgs e)
{
// Apply the new zoom/scroll settings
UpdateZoomAndScroll();
}
///
/// Event Handle form Vertical Scroll Value Changed Event
///
/// The control that raised the event.
/// The event arguments.
private void vScrollBar_ValueChanged(object sender, System.EventArgs e)
{
// Apply the new zoom/scroll settings
UpdateZoomAndScroll();
}
///
/// Event Handle from ApplyToPenWidth Click Event
///
/// The control that raised the event.
/// The event arguments.
private void miScalePenWidth_Click(object sender, System.EventArgs e)
{
// Toggle the value indicating whether to apply the zoom to pen width
// If on, use the view transform. Otherwise, use the object transform.
miScalePenWidth.Checked = !miScalePenWidth.Checked;
// Renderer's view and object transforms are used to perform
// zooming and scrolling. The view transform applies to the
// points and pen width. The object transform applies
// only to the points. Since the sample only uses one of these
// transforms at a time, it is necessary to clear out the unused
// transform and then invoke SetViewTransform to apply the
// zoom/scroll settings on the view or object transform
// (depending if pen width scaling is desired).
if (miScalePenWidth.Checked)
{
myInkCollector.Renderer.SetObjectTransform(null);
}
else
{
myInkCollector.Renderer.SetViewTransform(null);
}
// Apply the new zoom/scroll settings
UpdateZoomAndScroll();
}
///
/// Event Handle from Ink Click Event
///
/// The control that raised the event.
/// The event arguments.
private void miInk_Click(object sender, System.EventArgs e)
{
// Update the Mode menu to be in ink mode
miInk.Checked = true;
miZoomToRect.Checked = false;
// Update the cursor
// Note that it is necessary to use the full name to avoid a
// namespace conflict with InkCollector's Cursors property.
pnlDrawingArea.Cursor = System.Windows.Forms.Cursors.Default;
// Enable the ink collector
myInkCollector.Enabled = true;
}
///
/// Event Handle from ZoomToRect Click Event
///
/// The control that raised the event.
/// The event arguments.
private void miZoomToRect_Click(object sender, System.EventArgs e)
{
if (!myInkCollector.CollectingInk)
{
// Update the Mode menu to be in zoom to rect mode
miInk.Checked = false;
miZoomToRect.Checked = true;
// Update the cursor
pnlDrawingArea.Cursor = System.Windows.Forms.Cursors.Cross;
// Disable the ink collector
myInkCollector.Enabled = false;
}
else
{
// If user is actively inking, we cannot switch modes.
MessageBox.Show("Cannot Zoom while collecting ink.");
}
}
///
/// Event Handle from Clear Click Event
///
/// The control that raised the event.
/// The event arguments.
private void miClear_Click(object sender, System.EventArgs e)
{
// Set the zoom level to 100%
zoomFactor = 1;
// Set the scroll bars to the top left of the screen
hScrollBar.Value = 0;
vScrollBar.Value = 0;
zoomUpDown.Value = 100;
// remove all strokes from the ink collector
myInkCollector.Ink.DeleteStrokes();
// Apply the new zoom/scroll settings
UpdateZoomAndScroll();
// Reset the application mode to inking
miInk.Checked = true;
miZoomToRect.Checked = false;
Cursor = System.Windows.Forms.Cursors.Default;
myInkCollector.Enabled = true;
}
///
/// Event Handle from File->Exit Click Event
///
/// The control that raised the event.
/// The event arguments.
private void miExit_Click(object sender, System.EventArgs e)
{
myInkCollector.Enabled = false;
this.Dispose();
}
///
/// Event Handle from form's Resize Event
///
/// The control that raised the event.
/// The event arguments.
private void InkZoom_Resize(object sender, System.EventArgs e)
{
// If the user resizes the window, update the scroll
// bars to reflect the change. However, it is necessary
// to check whether the ink collector is null before
// invoking this method since the Resize event also occurs
// automatically before the ink collector is created.
if (myInkCollector!=null)
{
UpdateScrollBars();
}
}
///
/// Event Handle from MouseDown Event
///
/// The control that raised the event.
/// The event arguments.
private void pnlDrawingArea_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
{
// If the user has selected to draw a zoom rectangle, update
// the zoom rectangle's start point to the mouse location.
if (miZoomToRect.Checked)
{
zoomRectangle.Location = new Point(e.X,e.Y);
zoomRectangle.Width = 0;
zoomRectangle.Height = 0;
}
}
///
/// Event Handle from MouseMove event
///
/// The control that raised the event.
/// The event arguments.
private void pnlDrawingArea_MouseMove(object sender, System.Windows.Forms.MouseEventArgs e)
{
// If the user has selected to draw a zoom rectangle and has a mouse
// button pressed down, update the zoom rectangle end point to the
// new mouse location.
if ( (miZoomToRect.Checked) && (MouseButtons != MouseButtons.None) )
{
// Erase the previous zoom rectangle
Rectangle screenRect = zoomRectangle;
screenRect.Offset(pnlDrawingArea.PointToScreen(Point.Empty));
ControlPaint.DrawReversibleFrame(screenRect,Color.Transparent,FrameStyle.Dashed);
int xSize = e.X - zoomRectangle.Location.X;
int ySize = e.Y - zoomRectangle.Location.Y;
int zoomRectSize = Math.Max(Math.Abs(xSize),Math.Abs(ySize));
zoomRectangle.Width = (xSize>0)?zoomRectSize:-zoomRectSize;
zoomRectangle.Height = (ySize>0)?zoomRectSize:-zoomRectSize;
// Draw the current zoom rectangle
screenRect = zoomRectangle;
screenRect.Offset(pnlDrawingArea.PointToScreen(Point.Empty));
ControlPaint.DrawReversibleFrame(screenRect,Color.Transparent,FrameStyle.Dashed);
}
}
///
/// Event Handle from MouseUp Event
///
/// The control that raised the event.
/// The event arguments.
private void pnlDrawingArea_MouseUp(object sender, System.Windows.Forms.MouseEventArgs e)
{
// If the user has selected to draw a zoom rectangle...
if (miZoomToRect.Checked)
{
// Erase the zoom rectangle
Rectangle screenRect = zoomRectangle;
screenRect.Offset(pnlDrawingArea.PointToScreen(Point.Empty));
ControlPaint.DrawReversibleFrame(screenRect,Color.Transparent,FrameStyle.Dashed);
// Perform the zoom
ZoomToRectangle();
}
}
///
/// Helper method to update the ink collector with the current
/// zoom and scroll values
///
private void UpdateZoomAndScroll()
{
// Create a new transformation matrix
Matrix m = new Matrix();
// Apply the current scale factor
m.Scale(zoomFactor,zoomFactor);
// Apply the current translation factor - note that since
// the scroll bars map directly to ink space, their values
// can be used directly.
m.Translate(-hScrollBar.Value, -vScrollBar.Value);
// Renderer's view and object transforms are used to perform
// zooming and scrolling. The view transform applies to the
// points and pen width. The object transform applies
// only to the points. Depending on whether the user has
// selected to apply the transform to pen width, update the
// view or object transform.
if (miScalePenWidth.Checked)
{
myInkCollector.Renderer.SetViewTransform(m);
}
else
{
myInkCollector.Renderer.SetObjectTransform(m);
}
// Set the scroll bars to map to the current zoom level
UpdateScrollBars();
Refresh();
}
///
/// Helper method to update the scroll bars small and large change
/// values to the new zoom level. If the scroll bars are no longer
/// needed, this method will also hide them.
///
void UpdateScrollBars()
{
if ( (hScrollBar.Width>0) && (vScrollBar.Height>0))
{
// The following code sets the small and large change
// values of the scroll bars. These values specify
// desired scroll size when the scroll box is moved a
// small/large distance. In this sample, the large
// change scrolls by the width of the visible drawing
// area and the small change scrolls by the constant
// SmallChangeSize. Note that it is necessary to account
// for the zoom factor when calculating the large and
// small change values. Also, since the scroll bar
// uses ink space units, it is necessary to calculate
// the small and large change values in ink space.
//
// In summary:
// 1. Calculate the large change value as the width
// of the visible drawing area in ink space units.
// 2. Calculate the small change value as the
// SmallChangeSize in ink space units.
// Create a point representing the top left of the drawing area (in pixels)
Point ptUpperLeft = new Point(0, 0);
// Create a point representing the size of a small change
Point ptSmallChange = new Point(SmallChangeSize, SmallChangeSize);
// Create a point representing the bottom right of the drawing area (in pixels)
Point ptLowerRight = new Point(hScrollBar.Width, vScrollBar.Height);
using (Graphics g = CreateGraphics())
{
// Convert each of the points to ink space
myInkCollector.Renderer.PixelToInkSpace(g, ref ptUpperLeft);
myInkCollector.Renderer.PixelToInkSpace(g, ref ptLowerRight);
myInkCollector.Renderer.PixelToInkSpace(g, ref ptSmallChange);
}
// Set the SmallChange values (in ink space)
// Note that it is necessary to subract the upper left point
// value to account for scrolling.
hScrollBar.SmallChange = ptSmallChange.X - ptUpperLeft.X;
vScrollBar.SmallChange = ptSmallChange.Y - ptUpperLeft.Y;
// Set the LargeChange values to the drawing area width (in ink space)
// Note that it is necessary to subract the upper left point
// value to account for scrolling.
hScrollBar.LargeChange = ptLowerRight.X - ptUpperLeft.X;
vScrollBar.LargeChange = ptLowerRight.Y - ptUpperLeft.Y;
// If the scroll bars are not needed, hide them
hScrollBar.Visible = hScrollBar.LargeChange < hScrollBar.Maximum;
vScrollBar.Visible = vScrollBar.LargeChange < vScrollBar.Maximum;
// If the horizontal scroll bar value would run off of the drawing area,
// adjust it
if(hScrollBar.Visible && (hScrollBar.Value + hScrollBar.LargeChange > hScrollBar.Maximum))
{
hScrollBar.Value = hScrollBar.Maximum - hScrollBar.LargeChange;
}
// If the vertical scroll bar value would run off of the drawing area,
// adjust it
if(vScrollBar.Visible && (vScrollBar.Value + vScrollBar.LargeChange > vScrollBar.Maximum))
{
vScrollBar.Value = vScrollBar.Maximum - vScrollBar.LargeChange;
}
}
}
///
/// Helper method to zoom into a specified rectangle.
///
public void ZoomToRectangle()
{
// Calculate the width/height of the zoom rectangle
int newWidth = Math.Abs(zoomRectangle.Width);
int newHeight = Math.Abs(zoomRectangle.Height);
// Check to ensure that the zoom rectangle isn't just a point...
if (newWidth>0 && newHeight>0)
{
// To determine the new scale factor, take the ratio of the
// scaled drawing area to the size of the zoom rectangle.
// Since the ratio of the width could be different than
// the ratio of the height, the minimum scale value is used.
float newZoomFactor = Math.Min((zoomFactor*pnlDrawingArea.Width)/newWidth,
(zoomFactor*pnlDrawingArea.Height)/newHeight);
// Check whether the zoom rectangle would exceed the allowable
// zoom level. If so, display an error.
if ((int)(newZoomFactor*100) < zoomUpDown.Minimum)
{
MessageBox.Show("Minimum zoom level reached.");
}
else if ((int)(newZoomFactor*100) > zoomUpDown.Maximum)
{
MessageBox.Show("Maximum zoom level reached.");
}
else
{
// Set the scroll bar values to the zoom rectangle's top left corner
// Note that it is necessary to convert to ink space since the scroll
// bars use ink space coordinates.
Point scrollValue = new Point();
scrollValue.X = Math.Min(zoomRectangle.Left,zoomRectangle.Left + zoomRectangle.Width);
scrollValue.Y = Math.Min(zoomRectangle.Top,zoomRectangle.Top + zoomRectangle.Height);
using (Graphics g = CreateGraphics())
{
myInkCollector.Renderer.PixelToInkSpace(g,ref scrollValue);
}
// If the new scroll bar values would fall outside of the
// allowable range, adjust them to the nearest allowable
// value.
if (scrollValue.X > hScrollBar.Maximum)
{
scrollValue.X = hScrollBar.Maximum;
}
else if (scrollValue.X < hScrollBar.Minimum)
{
scrollValue.X = hScrollBar.Minimum;
}
if (scrollValue.Y > vScrollBar.Maximum)
{
scrollValue.Y = vScrollBar.Maximum;
}
else if (scrollValue.Y < vScrollBar.Minimum)
{
scrollValue.Y = vScrollBar.Minimum;
}
// Update the new scale factor to the ratio of the scroll bar
// to the zoom rectangle's width
zoomFactor = newZoomFactor;
zoomUpDown.Value = (decimal)zoomFactor*100;
// Apply the new zoom/scroll settings
UpdateZoomAndScroll();
// Update the scroll bar values.
hScrollBar.Value = scrollValue.X;
vScrollBar.Value = scrollValue.Y;
}
}
// Reset the zoom rectangle
zoomRectangle = Rectangle.Empty;
Refresh();
}
}
}