Code:
/ 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / Misc / GDI / DeviceContext2.cs / 1305376 / DeviceContext2.cs
//------------------------------------------------------------------------------
//
// Copyright (c) Microsoft Corporation. All rights reserved.
//
//-----------------------------------------------------------------------------
#if [....]_NAMESPACE
namespace System.Windows.Forms.Internal
#elif DRAWING_NAMESPACE
namespace System.Drawing.Internal
#else
namespace System.Experimental.Gdi
#endif
{
using System;
using System.Internal;
using System.Security;
using System.Runtime.InteropServices;
using System.Diagnostics;
using System.ComponentModel;
using System.Drawing;
using System.Globalization;
using System.Runtime.Versioning;
///
/// Represents a Win32 device context. Provides operations for setting some of the properties
/// of a device context. It's the managed wrapper for an HDC.
///
/// This class is divided into two files separating the code that needs to be compiled into
/// reatail builds and debugging code.
///
/// WARNING: The properties of the dc are obtained on-demand, this object is light-weight because
/// of that; if you need to put back the old value after changing a property you need to get it
/// first and cache it.
///
#if [....]_PUBLIC_GRAPHICS_LIBRARY
public
#else
internal
#endif
sealed partial class DeviceContext : MarshalByRefObject, IDeviceContext, IDisposable
{
WindowsFont selectedFont;
///
/// See DeviceContext.cs for information about this class. The class has been split to be able
/// to compile the right set of functionalities into different assemblies.
///
public WindowsFont ActiveFont {
get {
return selectedFont;
}
}
///
/// DC background color.
///
public Color BackgroundColor
{
get
{
return ColorTranslator.FromWin32(IntUnsafeNativeMethods.GetBkColor( new HandleRef( this, this.Hdc )));
}
#if [....]_PUBLIC_GRAPHICS_LIBRARY
set
{
SetBackgroundColor( value );
}
#endif
}
///
/// Sets the DC background color and returns the old value.
///
public Color SetBackgroundColor( Color newColor )
{
return ColorTranslator.FromWin32(IntUnsafeNativeMethods.SetBkColor( new HandleRef( this, this.Hdc ), ColorTranslator.ToWin32(newColor)));
}
///
/// DC background mode.
///
public DeviceContextBackgroundMode BackgroundMode
{
get
{
return (DeviceContextBackgroundMode) IntUnsafeNativeMethods.GetBkMode( new HandleRef( this, this.Hdc ) );
}
#if [....]_PUBLIC_GRAPHICS_LIBRARY
set
{
SetBackgroundMode(value);
}
#endif
}
///
/// Sets the DC background mode and returns the old value.
///
public DeviceContextBackgroundMode SetBackgroundMode( DeviceContextBackgroundMode newMode )
{
return (DeviceContextBackgroundMode) IntUnsafeNativeMethods.SetBkMode(new HandleRef(this, this.Hdc), (int) newMode);
}
///
/// ROP2 currently on the DC.
///
public DeviceContextBinaryRasterOperationFlags BinaryRasterOperation
{
get
{
return (DeviceContextBinaryRasterOperationFlags) IntUnsafeNativeMethods.GetROP2( new HandleRef( this, this.Hdc ) );
}
/*
*
*/
}
///
/// Sets the DC ROP2 and returns the old value.
///
public DeviceContextBinaryRasterOperationFlags SetRasterOperation(DeviceContextBinaryRasterOperationFlags rasterOperation )
{
return (DeviceContextBinaryRasterOperationFlags) IntUnsafeNativeMethods.SetROP2(new HandleRef(this, this.Hdc), (int) rasterOperation);
}
///
/// Get the number of pixels per logical inch along the device axes.
/// In a system with multiple display monitors, this value is the same for all monitors.
///
public Size Dpi
{
get
{
return new Size(GetDeviceCapabilities(DeviceCapabilities.LogicalPixelsX), GetDeviceCapabilities(DeviceCapabilities.LogicalPixelsY));
}
}
///
/// Get the number of pixels per logical inch along the device width.
/// In a system with multiple display monitors, this value is the same for all monitors.
///
public int DpiX
{
get
{
return GetDeviceCapabilities(DeviceCapabilities.LogicalPixelsX);
}
}
///
/// Get the number of pixels per logical inch along the device (screen) height.
/// In a system with multiple display monitors, this value is the same for all monitors.
///
public int DpiY
{
get
{
return GetDeviceCapabilities(DeviceCapabilities.LogicalPixelsY);
}
}
///
/// The font selected into the device context.
/// It's OK to call dispose on it, the HFONT won't be deleted since the WindowsFont did not create it,
/// it got it from the HDC.
///
public WindowsFont Font
{
[ResourceExposure(ResourceScope.Process)]
[ResourceConsumption(ResourceScope.Process)]
get
{
#if OPTIMIZED_MEASUREMENTDC
if (MeasurementDCInfo.IsMeasurementDC(this))
{
WindowsFont font = MeasurementDCInfo.LastUsedFont;
if (font != null && (font.Hfont != IntPtr.Zero)) {
#if DEBUG
WindowsFont currentDCFont = WindowsFont.FromHdc( this.Hdc );
if (!font.Equals(currentDCFont) ) {
// just use the face name, as ToString will call here re-entrantly.
string lastUsedFontInfo = (font != null) ? font.Name : "null";
string currentFontInfo = (currentDCFont != null) ? currentDCFont.Name : "null";
Debug.Fail("Font does not match... Current: " + currentFontInfo + " Last known: " + lastUsedFontInfo);
}
#endif
return font;
}
}
#endif
// Returns the currently selected object in the dc.
// Note: for common DCs, GetDC assigns default attributes to the DC each time it is retrieved,
// the default font is System.
return WindowsFont.FromHdc( this.Hdc );
}
#if [....]_PUBLIC_GRAPHICS_LIBRARY
set
{
Debug.Assert( value != null, "value == null." );
IntPtr hOldFont = SelectFont( value );
IntUnsafeNativeMethods.IntDeleteObject(new HandleRef(null, hOldFont));
}
#endif
}
///
/// Gets a DeviceContext object initialized to refer to the primary screen device.
/// Consider using WindowsGraphicsCacheManager.MeasurementGraphics instead.
///
public static DeviceContext ScreenDC
{
get
{
return DeviceContext.FromHwnd(IntPtr.Zero);
}
}
internal void DisposeFont(bool disposing) {
if (disposing) {
DeviceContexts.RemoveDeviceContext(this);
}
if (selectedFont != null && selectedFont.Hfont != IntPtr.Zero) {
IntPtr hCurrentFont = IntUnsafeNativeMethods.GetCurrentObject(new HandleRef(this, hDC), IntNativeMethods.OBJ_FONT);
if (hCurrentFont == selectedFont.Hfont) {
// select initial font back in
IntUnsafeNativeMethods.SelectObject(new HandleRef(this, this.Hdc), new HandleRef( null, hInitialFont));
hCurrentFont = hInitialFont;
}
selectedFont.Dispose(disposing);
selectedFont = null;
}
}
///
/// Selects the specified object into the dc. If the specified object is the same as the one currently selected
/// in the dc, the object is not set and a null value is returned.
///
public IntPtr SelectFont( WindowsFont font )
{
// Fonts are one of the most expensive objects to select in an hdc and in many cases we are passed a Font that is the
// same as the one already selected in the dc so to avoid a perf hit we get the hdc font's log font and compare it
// with the one passed in before selecting it in the hdc.
// Also, we avoid performing GDI operations that if done on an enhanced metafile DC would add an entry to it, hence
// reducing the size of the metafile.
if( font.Equals( this.Font ))
{
return IntPtr.Zero;
}
IntPtr result = SelectObject( font.Hfont, GdiObjectType.Font);
WindowsFont previousFont = selectedFont;
selectedFont = font;
hCurrentFont = font.Hfont;
// the measurement DC always leaves fonts selected for pref reasons.
// in this case, we need to diposse the font since the original
// creator didn't fully dispose.
if (previousFont != null) {
#if DEBUG
//Disabling this assert until DevDiv Bugs 95968 gets fixed
//Debug.Assert(previousFont.Hfont != IntPtr.Zero, "A font has been disposed before it was unselected from the DC. This will leak a GDI handle on Win9x! Call ResetFont()");
#endif
if (MeasurementDCInfo.IsMeasurementDC(this)) {
previousFont.Dispose();
}
}
#if OPTIMIZED_MEASUREMENTDC
// once we've changed the font, update the last used font.
if (MeasurementDCInfo.IsMeasurementDC(this))
{
if (result != IntPtr.Zero)
{
MeasurementDCInfo.LastUsedFont = font;
}
else
{
// there was an error selecting the Font into the DC, we dont know anything about it.
MeasurementDCInfo.Reset();
}
}
#endif
return result;
}
public void ResetFont()
{
#if OPTIMIZED_MEASUREMENTDC
// in this case, GDI will copy back the previously saved font into the DC.
// we dont actually know what the font is in our measurement DC so
// we need to clear it off.
MeasurementDCInfo.ResetIfIsMeasurementDC(this.Hdc);
#endif
IntUnsafeNativeMethods.SelectObject(new HandleRef(this, this.Hdc), new HandleRef( null, hInitialFont ));
selectedFont = null;
hCurrentFont = hInitialFont;
}
///
/// Retrieves device-specific information for this device.
///
public int GetDeviceCapabilities( DeviceCapabilities capabilityIndex )
{
return IntUnsafeNativeMethods.GetDeviceCaps( new HandleRef( this, this.Hdc ), (int) capabilityIndex );
}
///
/// DC map mode.
///
public DeviceContextMapMode MapMode
{
get
{
return (DeviceContextMapMode) IntUnsafeNativeMethods.GetMapMode( new HandleRef( this, this.Hdc ) );
}
#if [....]_PUBLIC_GRAPHICS_LIBRARY
set
{
SetMapMode(value);
}
#endif
}
public bool IsFontOnContextStack(WindowsFont wf)
{
if (contextStack == null) {
return false;
}
foreach (GraphicsState g in contextStack) {
if (g.hFont == wf.Hfont) {
return true;
}
}
return false;
}
///
/// Sets the DC map mode and returns the old value.
///
public DeviceContextMapMode SetMapMode( DeviceContextMapMode newMode )
{
return (DeviceContextMapMode) IntUnsafeNativeMethods.SetMapMode( new HandleRef(this, this.Hdc), (int) newMode );
}
///
/// Selects the specified object into the dc and returns the old object.
///
public IntPtr SelectObject(IntPtr hObj, GdiObjectType type)
{
switch (type) {
case GdiObjectType.Pen:
hCurrentPen = hObj;
break;
case GdiObjectType.Brush:
hCurrentBrush = hObj;
break;
case GdiObjectType.Bitmap:
hCurrentBmp = hObj;
break;
}
return IntUnsafeNativeMethods.SelectObject(new HandleRef(this, this.Hdc), new HandleRef( null, hObj));
}
///
/// DC text alignment.
///
public DeviceContextTextAlignment TextAlignment
{
get
{
return (DeviceContextTextAlignment) IntUnsafeNativeMethods.GetTextAlign( new HandleRef( this, this.Hdc ) );
}
#if [....]_PUBLIC_GRAPHICS_LIBRARY
set
{
SetTextAlignment(value);
}
#endif
}
///
/// Sets the DC text alignment and returns the old value.
///
public DeviceContextTextAlignment SetTextAlignment( DeviceContextTextAlignment newAligment )
{
return (DeviceContextTextAlignment) IntUnsafeNativeMethods.SetTextAlign(new HandleRef(this, this.Hdc), (int) newAligment );
}
///
/// DC current text color.
///
public Color TextColor
{
get
{
return ColorTranslator.FromWin32(IntUnsafeNativeMethods.GetTextColor( new HandleRef( this, this.Hdc ) ));
}
#if [....]_PUBLIC_GRAPHICS_LIBRARY
set
{
SetTextColor(value);
}
#endif
}
///
/// Sets the DC text color and returns the old value.
///
public Color SetTextColor( Color newColor )
{
return ColorTranslator.FromWin32(IntUnsafeNativeMethods.SetTextColor(new HandleRef( this, this.Hdc), ColorTranslator.ToWin32(newColor)));
}
///
/// DC Viewport Extent in device units.
///
public Size ViewportExtent
{
get
{
IntNativeMethods.SIZE size = new IntNativeMethods.SIZE();
IntUnsafeNativeMethods.GetViewportExtEx( new HandleRef( this, this.Hdc ), size );
return size.ToSize();
}
set
{
SetViewportExtent( value );
}
}
///
/// Sets the DC Viewport extent to the specified value and returns its previous value; extent values are in device units.
///
public Size SetViewportExtent( Size newExtent )
{
IntNativeMethods.SIZE oldExtent = new IntNativeMethods.SIZE();
IntUnsafeNativeMethods.SetViewportExtEx( new HandleRef( this, this.Hdc ), newExtent.Width, newExtent.Height, oldExtent );
return oldExtent.ToSize();
}
///
/// DC Viewport Origin in device units.
///
public Point ViewportOrigin
{
get
{
IntNativeMethods.POINT point = new IntNativeMethods.POINT();
IntUnsafeNativeMethods.GetViewportOrgEx( new HandleRef( this, this.Hdc ), point );
return point.ToPoint();
}
set
{
SetViewportOrigin( value );
}
}
///
/// Sets the DC Viewport origin to the specified value and returns its previous value; origin values are in device units.
///
public Point SetViewportOrigin( Point newOrigin )
{
IntNativeMethods.POINT oldOrigin = new IntNativeMethods.POINT();
IntUnsafeNativeMethods.SetViewportOrgEx( new HandleRef( this, this.Hdc ), newOrigin.X, newOrigin.Y, oldOrigin );
return oldOrigin.ToPoint();
}
}
}
// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
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