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//---------------------------------------------------------------------------
//
// <copyright file="SplashScreen.cs" company="Microsoft">
// Copyright (C) Microsoft Corporation. All rights reserved.
// </copyright>
//
// Description:
//
// History:
// 02/18/2008: Microsoft: Created
//
//---------------------------------------------------------------------------
using System.ComponentModel;
using System.IO;
using System.Reflection;
using System.Resources;
using System.Runtime.InteropServices;
using System.Security;
using System.Security.Permissions;
using System.Windows.Threading;
using MS.Internal;
using MS.Internal.Interop;
using MS.Internal.KnownBoxes;
using MS.Internal.WindowsBase;
using MS.Utility;
using MS.Win32;
namespace System.Windows
{
/// <SecurityNote>
/// This class has been reviewed under the assumption that it is not used in partial trust.
/// If this changes all methods will need to be re-reviewed.
/// </SecurityNote>
[SecurityCritical(SecurityCriticalScope.Everything)]
[UIPermission(SecurityAction.LinkDemand, Window=UIPermissionWindow.AllWindows)]
public class SplashScreen
{
private IntPtr _hwnd = IntPtr.Zero;
private string _resourceName;
private IntPtr _hInstance;
private NativeMethods.BitmapHandle _hBitmap;
private ushort _wndClass;
private DispatcherTimer _dt;
private TimeSpan _fadeoutDuration;
private DateTime _fadeoutEnd;
NativeMethods.BLENDFUNCTION _blendFunc;
private ResourceManager _resourceManager;
private Dispatcher _dispatcher;
// keep this delegate alive as long as the window class is registered
private static NativeMethods.WndProc _defWndProc;
private const string CLASSNAME = "SplashScreen";
/// <SecurityNote>
/// Critical - Calls critical ctor overload.
/// </SecurityNote>
[SecurityCritical]
public SplashScreen(string resourceName) : this(Assembly.GetEntryAssembly(), resourceName)
{
}
/// <SecurityNote>
/// Critical: Calls Marshal.GetHINSTANCE
/// PublicOK: Does not expose HINSTANCE.
/// Not available in partial trust.
/// </SecurityNote>
[SecurityCritical]
public SplashScreen(Assembly resourceAssembly, string resourceName)
{
if (resourceAssembly == null)
{
throw new ArgumentNullException("resourceAssembly");
}
if (String.IsNullOrEmpty(resourceName))
{
throw new ArgumentNullException("resourceName");
}
_resourceName = resourceName.ToLowerInvariant();
_hInstance = Marshal.GetHINSTANCE(resourceAssembly.ManifestModule);
AssemblyName name = new AssemblyName(resourceAssembly.FullName);
_resourceManager = new ResourceManager(name.Name + ".g", resourceAssembly);
}
/// <SecurityNote>
/// Critical - Calls critical Show overload.
/// </SecurityNote>
[SecurityCritical]
public void Show(bool autoClose)
{
Show(autoClose, false);
}
/// <SecurityNote>
/// Critical: Calls CreateLayeredWindowFromImgBuffer
/// PublicOk: This class is not available in partial trust.
/// The created window handle is not exposed.
///
/// </SecurityNote>
[SecurityCritical]
public void Show(bool autoClose, bool topMost)
{
// If we've already been shown it isn't an error to call show
// again (maybe you forgot) since you will still be shown state.
if (_hwnd == IntPtr.Zero)
{
UnmanagedMemoryStream umemStream;
using (umemStream = GetResourceStream())
{
if (umemStream != null)
{
umemStream.Seek(0, SeekOrigin.Begin); // ensure stream position
IntPtr pImageSrcBuffer;
unsafe
{
pImageSrcBuffer = new IntPtr(umemStream.PositionPointer);
}
if (CreateLayeredWindowFromImgBuffer(pImageSrcBuffer, umemStream.Length, topMost) && autoClose == true)
{
Dispatcher.CurrentDispatcher.BeginInvoke(
DispatcherPriority.Loaded,
(DispatcherOperationCallback)ShowCallback,
this);
}
// The HWND that we just created is owned by this thread. When we close we should ensure that it
// does not get accessed from a different thread. We don't want to reference the .CurrentDispatcher
// property before the window is created due to cold start performance concerns.
_dispatcher = Dispatcher.CurrentDispatcher;
}
else
{
throw new IOException(SR.Get(SRID.UnableToLocateResource, _resourceName));
}
}
}
}
/// <SecurityNote>
/// Critical - Calls critical SplashScreen.Close.
/// </SecurityNote>
[SecurityCritical]
private static object ShowCallback(object arg)
{
SplashScreen splashScreen = (SplashScreen)arg;
splashScreen.Close(TimeSpan.FromSeconds(0.3));
return null;
}
// This is 200-300 ms slower than Assembly.GetManifestResourceStream() but works with localization.
private UnmanagedMemoryStream GetResourceStream()
{
// Try to get the stream with the string the developer supplied, in the app.g.cs case
// this will always work.
UnmanagedMemoryStream stream = _resourceManager.GetStream(_resourceName, System.Globalization.CultureInfo.CurrentUICulture);
if (stream != null)
{
return stream;
}
// IF that fails then the resource name had special characters in it which would not
// be encoded literally into the resource stream. Unfortunately we need to rely on the
// slow URI class to get the correct name. We try to avoid doing this in the common case
// since URI has quite a bit of code associated with it.
string resourceName = ResourceIDHelper.GetResourceIDFromRelativePath(_resourceName);
return _resourceManager.GetStream(resourceName, System.Globalization.CultureInfo.CurrentUICulture);
}
/// <SecurityNote>
/// Critical: Calls UnsafeNativeMethods to create and update a layered window.
/// Manipulates native objects passed in.
/// </SecurityNote>
[SecurityCritical]
private IntPtr CreateWindow(NativeMethods.BitmapHandle hBitmap, int width, int height, bool topMost)
{
if (_defWndProc == null)
{
_defWndProc = new MS.Win32.NativeMethods.WndProc(UnsafeNativeMethods.DefWindowProc);
}
MS.Win32.NativeMethods.WNDCLASSEX_D wndClass = new MS.Win32.NativeMethods.WNDCLASSEX_D();
wndClass.cbSize = Marshal.SizeOf(typeof(MS.Win32.NativeMethods.WNDCLASSEX_D));
wndClass.style = 3; /* CS_HREDRAW | CS_VREDRAW */
wndClass.lpfnWndProc = null;
wndClass.hInstance = _hInstance;
wndClass.hCursor = IntPtr.Zero;
wndClass.lpszClassName = CLASSNAME;
wndClass.lpszMenuName = string.Empty;
wndClass.lpfnWndProc = _defWndProc;
// We chose to ignore re-registration errors in RegisterClassEx on the off chance that the user
// wants to open multiple splash screens.
_wndClass = MS.Win32.UnsafeNativeMethods.IntRegisterClassEx(wndClass);
if (_wndClass == 0)
{
if (Marshal.GetLastWin32Error() != 0x582) /* class already registered */
throw new Win32Exception();
}
int screenWidth = MS.Win32.UnsafeNativeMethods.GetSystemMetrics(SM.CXSCREEN);
int screenHeight = MS.Win32.UnsafeNativeMethods.GetSystemMetrics(SM.CYSCREEN);
int x = (screenWidth - width) / 2;
int y = (screenHeight - height) / 2;
HandleRef nullHandle = new HandleRef(null, IntPtr.Zero);
int windowCreateFlags =
(int) NativeMethods.WS_EX_WINDOWEDGE |
NativeMethods.WS_EX_TOOLWINDOW |
NativeMethods.WS_EX_LAYERED |
(topMost ? NativeMethods.WS_EX_TOPMOST : 0);
// CreateWindowEx will either succeed or throw
IntPtr hWnd = MS.Win32.UnsafeNativeMethods.CreateWindowEx(
windowCreateFlags,
CLASSNAME, SR.Get(SRID.SplashScreenIsLoading),
MS.Win32.NativeMethods.WS_POPUP | MS.Win32.NativeMethods.WS_VISIBLE,
x, y, width, height,
nullHandle, nullHandle, new HandleRef(null, _hInstance), IntPtr.Zero);
// Display the image on the window
IntPtr hScreenDC = UnsafeNativeMethods.GetDC(new HandleRef());
IntPtr memDC = UnsafeNativeMethods.CreateCompatibleDC(new HandleRef(null, hScreenDC));
IntPtr hOldBitmap = UnsafeNativeMethods.SelectObject(new HandleRef(null, memDC), hBitmap.MakeHandleRef(null).Handle);
NativeMethods.POINT newSize = new NativeMethods.POINT(width, height);
NativeMethods.POINT newLocation = new NativeMethods.POINT(x, y);
NativeMethods.POINT sourceLocation = new NativeMethods.POINT(0, 0);
_blendFunc = new NativeMethods.BLENDFUNCTION();
_blendFunc.BlendOp = NativeMethods.AC_SRC_OVER;
_blendFunc.BlendFlags = 0;
_blendFunc.SourceConstantAlpha = 255;
_blendFunc.AlphaFormat = 1; /*AC_SRC_ALPHA*/
bool result = UnsafeNativeMethods.UpdateLayeredWindow(hWnd, hScreenDC, newLocation, newSize,
memDC, sourceLocation, 0, ref _blendFunc, NativeMethods.ULW_ALPHA);
UnsafeNativeMethods.SelectObject(new HandleRef(null, memDC), hOldBitmap);
UnsafeNativeMethods.ReleaseDC(new HandleRef(), new HandleRef(null, memDC));
UnsafeNativeMethods.ReleaseDC(new HandleRef(), new HandleRef(null, hScreenDC));
if (result == false)
{
UnsafeNativeMethods.HRESULT.Check(Marshal.GetHRForLastWin32Error());
}
return hWnd;
}
/// <SecurityNote>
/// Critical: Calls critical CloseInternal
/// PublicOK: Only the splash screen window can be activated.
/// This class is not available in partial trust.
/// </SecurityNote>
[SecurityCritical]
public void Close(TimeSpan fadeoutDuration)
{
object result = null;
if (_dispatcher != null)
{
if (_dispatcher.CheckAccess())
{
result = CloseInternal(fadeoutDuration);
}
else
{
result = _dispatcher.Invoke(DispatcherPriority.Normal, (DispatcherOperationCallback)CloseInternal, fadeoutDuration);
}
}
if (result != BooleanBoxes.TrueBox)
{
// If all else fails try to destroy the resources on this thread
// this will probably end up throwing but it will be the same
// exception as the previous version.
DestroyResources();
}
}
/// <SecurityNote>
/// Critical: P-Invokes SetActiveWindow to make sure the fade out animation is visible (if a fade out is specified)
/// </SecurityNote>
[SecurityCritical]
private object CloseInternal(Object fadeOutArg)
{
TimeSpan fadeoutDuration = (TimeSpan) fadeOutArg;
if (fadeoutDuration <= TimeSpan.Zero)
{
DestroyResources();
return BooleanBoxes.TrueBox;
}
// In the case where the developer has specified AutoClose=True and then calls
// Close(non_zero_timespan) before the auto close operation is dispatched we begin
// the fadeout immidiately and ignore the later call to close.
if (_dt != null || _hwnd == null)
{
return BooleanBoxes.TrueBox;
}
// by default close gets called as soon as the first application window is created
// since it will have become the active window we need to steal back the active window
// status so that the fade out animation is visible.
IntPtr prevHwnd = UnsafeNativeMethods.SetActiveWindow(new HandleRef(null, _hwnd));
if (prevHwnd == IntPtr.Zero)
{
// SetActiveWindow fails (returns NULL) if the application is not in the foreground.
// If this is the case, don't bother animating the fade out.
DestroyResources();
return BooleanBoxes.TrueBox;
}
_dt = new DispatcherTimer();
_dt.Interval = TimeSpan.FromMilliseconds(30); // shoot for ~30 fps
_fadeoutDuration = fadeoutDuration;
_fadeoutEnd = DateTime.UtcNow + _fadeoutDuration;
_dt.Tick += new EventHandler(Fadeout_Tick);
_dt.Start();
return BooleanBoxes.TrueBox;
}
/// <SecurityNote>
/// Critical: Calls UpdateLayeredWindow to set a new opacity.
/// TreatAsSafe: The layered window is not exposed to the user for tampering and setting the opacity of
/// the splash screen is not dangerous.
/// This class is not available in partial trust.
/// </SecurityNote>
[SecurityCritical, SecurityTreatAsSafe]
private void Fadeout_Tick(object unused, EventArgs args)
{
DateTime dtNow = DateTime.UtcNow;
if (dtNow >= _fadeoutEnd)
{
DestroyResources();
}
else
{
double progress = (_fadeoutEnd - dtNow).TotalMilliseconds / _fadeoutDuration.TotalMilliseconds;
_blendFunc.SourceConstantAlpha = (byte)(255 * progress);
UnsafeNativeMethods.UpdateLayeredWindow(_hwnd, IntPtr.Zero, null, null, IntPtr.Zero, null, 0, ref _blendFunc, NativeMethods.ULW_ALPHA);
}
}
/// <SecurityNote>
/// Critical: Calls into UnsafeNativeMethods to free resources
/// TreatAsSafe: Only frees resources allocated by this class and stored privately.
/// Checks that resource pointers are valid before attempting to free them.
/// </SecurityNote>
[SecurityCritical, SecurityTreatAsSafe]
private void DestroyResources()
{
if (_dt != null)
{
_dt.Stop();
_dt = null;
}
if (_hwnd != IntPtr.Zero)
{
HandleRef hwnd = new HandleRef(null, _hwnd);
if (UnsafeNativeMethods.IsWindow(hwnd))
{
UnsafeNativeMethods.IntDestroyWindow(hwnd);
}
_hwnd = IntPtr.Zero;
}
if (_hBitmap != null && !_hBitmap.IsClosed)
{
UnsafeNativeMethods.DeleteObject(_hBitmap.MakeHandleRef(null).Handle);
_hBitmap.Close();
_hBitmap = null;
}
if (_wndClass != 0)
{
// Attempt to unregister the window class. If the application has a second
// splash screen which is still open this call will fail. That's OK.
if (UnsafeNativeMethods.IntUnregisterClass(new IntPtr(_wndClass), _hInstance) != 0)
{
_defWndProc = null; // Can safely release the wndproc delegate when there are no more splash screen instances
}
_wndClass = 0;
}
if (_resourceManager != null)
{
_resourceManager.ReleaseAllResources();
}
}
/// <SecurityNote>
/// Critical: Calls out to WIC to decode the image buffer.
/// Calls out to several other UnsafeNativeMethods to get DC and create a DDB.
/// </SecurityNote>
[SecurityCritical]
private bool CreateLayeredWindowFromImgBuffer(IntPtr pImgBuffer, long cImgBufferLen, bool topMost)
{
bool bSuccess = false;
IntPtr pImagingFactory = IntPtr.Zero;
IntPtr pDecoder = IntPtr.Zero;
IntPtr pIStream = IntPtr.Zero;
IntPtr pDecodedFrame = IntPtr.Zero;
IntPtr pBitmapSourceFormatConverter = IntPtr.Zero;
IntPtr pBitmapFlipRotator = IntPtr.Zero;
try
{
UnsafeNativeMethods.HRESULT.Check(
UnsafeNativeMethods.WIC.CreateImagingFactory(UnsafeNativeMethods.WIC.WINCODEC_SDK_VERSION, out pImagingFactory));
// Use the WIC stream class to wrap the unmanaged pointer
UnsafeNativeMethods.HRESULT.Check(
UnsafeNativeMethods.WIC.CreateStream(pImagingFactory, out pIStream));
UnsafeNativeMethods.HRESULT.Check(
UnsafeNativeMethods.WIC.InitializeStreamFromMemory(pIStream, pImgBuffer, (uint)cImgBufferLen));
// Create an object that will decode the encoded image
Guid vendor = Guid.Empty;
UnsafeNativeMethods.HRESULT.Check(
UnsafeNativeMethods.WIC.CreateDecoderFromStream(pImagingFactory, pIStream,
ref vendor, 0, out pDecoder));
// Get the frame from the decoder. Most image formats have only a single frame, in the case
// of animated gifs we are ok with only displaying the first frame of the animation.
UnsafeNativeMethods.HRESULT.Check(
UnsafeNativeMethods.WIC.GetFrame(pDecoder, 0, out pDecodedFrame));
UnsafeNativeMethods.HRESULT.Check(
UnsafeNativeMethods.WIC.CreateFormatConverter(pImagingFactory, out pBitmapSourceFormatConverter));
// Convert the image from whatever format it is in to 32bpp premultiplied alpha BGRA
Guid pixelFormat = UnsafeNativeMethods.WIC.WICPixelFormat32bppPBGRA;
UnsafeNativeMethods.HRESULT.Check(
UnsafeNativeMethods.WIC.InitializeFormatConverter(pBitmapSourceFormatConverter, pDecodedFrame,
ref pixelFormat, 0 /*DitherTypeNone*/, IntPtr.Zero,
0, UnsafeNativeMethods.WIC.WICPaletteType.WICPaletteTypeCustom));
// Reorient the image
UnsafeNativeMethods.HRESULT.Check(
UnsafeNativeMethods.WIC.CreateBitmapFlipRotator(pImagingFactory, out pBitmapFlipRotator));
UnsafeNativeMethods.HRESULT.Check(
UnsafeNativeMethods.WIC.InitializeBitmapFlipRotator(pBitmapFlipRotator, pBitmapSourceFormatConverter,
UnsafeNativeMethods.WIC.WICBitmapTransformOptions.WICBitmapTransformFlipVertical));
Int32 width, height;
UnsafeNativeMethods.HRESULT.Check(
UnsafeNativeMethods.WIC.GetBitmapSize(pBitmapFlipRotator, out width, out height));
Int32 stride = width * 4;
// initialize the bitmap header
MS.Win32.NativeMethods.BITMAPINFO bmInfo = new MS.Win32.NativeMethods.BITMAPINFO(width, height, 32 /*bpp*/);
bmInfo.bmiHeader_biCompression = MS.Win32.NativeMethods.BI_RGB;
bmInfo.bmiHeader_biSizeImage = (int)(stride * height);
// Create a 32bpp DIB. This DIB must have an alpha channel for UpdateLayeredWindow to succeed.
IntPtr pBitmapBits = IntPtr.Zero;
_hBitmap = UnsafeNativeMethods.CreateDIBSection(new HandleRef(), ref bmInfo, 0 /* DIB_RGB_COLORS*/, ref pBitmapBits, null, 0);
// Copy the decoded image to the new buffer which backs the HBITMAP
Int32Rect rect = new Int32Rect(0, 0, width, height);
UnsafeNativeMethods.HRESULT.Check(
UnsafeNativeMethods.WIC.CopyPixels(pBitmapFlipRotator, ref rect, stride, stride * height, pBitmapBits));
_hwnd = CreateWindow(_hBitmap, width, height, topMost);
bSuccess = true;
}
finally
{
if (pImagingFactory != IntPtr.Zero)
{
Marshal.Release(pImagingFactory);
}
if (pDecoder != IntPtr.Zero)
{
Marshal.Release(pDecoder);
}
if (pIStream != IntPtr.Zero)
{
Marshal.Release(pIStream);
}
if (pDecodedFrame != IntPtr.Zero)
{
Marshal.Release(pDecodedFrame);
}
if (pBitmapSourceFormatConverter != IntPtr.Zero)
{
Marshal.Release(pBitmapSourceFormatConverter);
}
if (pBitmapFlipRotator != IntPtr.Zero)
{
Marshal.Release(pBitmapFlipRotator);
}
if (bSuccess == false)
{
DestroyResources(); // cleans up _hwnd and _hBitmap
}
}
return bSuccess;
}
}
}
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