using System;
using System.Runtime.InteropServices;

namespace Vanara.PInvoke
{
	public static partial class Shell32
	{
		/// <summary>
		/// Provides methods that enable apps to be informed of state changes and location for the input pane. The input pane is a UI
		/// element, an on-screen keyboard or handwriting panel, that appears when the user performs an action that requires them to enter
		/// information, such as selecting a search box or an entry field in a form. Apps can then adjust their UI so that the input pane
		/// does not obscure items that the user might need to access while the input pane is shown.
		/// </summary>
		/// <remarks>
		/// <para>When to implement</para>
		/// <para>Do not implement this interface; the implementation is supplied with Windows as CLSID_FrameworkInputPane.</para>
		/// </remarks>
		// https://docs.microsoft.com/en-us/windows/win32/api/shobjidl_core/nn-shobjidl_core-iframeworkinputpane
		[PInvokeData("shobjidl_core.h", MSDNShortId = "NN:shobjidl_core.IFrameworkInputPane")]
		[ComImport, Guid("5752238B-24F0-495A-82F1-2FD593056796"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown), CoClass(typeof(FrameworkInputPane))]
		public interface IFrameworkInputPane
		{
			/// <summary>
			/// Registers the app's input pane handler object to receive notifications on behalf of a window when an event triggers the
			/// input pane. This method differs from AdviseWithHWND in that it references its window through an object that implements ICoreWindow.
			/// </summary>
			/// <param name="pWindow">
			/// <para>Type: <c>IUnknown*</c></para>
			/// <para>
			/// A pointer to the window (an object that implements ICoreWindow) for which the handler should listen for input pane events.
			/// </para>
			/// </param>
			/// <param name="pHandler">
			/// <para>Type: <c>IFrameworkInputPaneHandler*</c></para>
			/// <para>An IFrameworkInputPaneHandler interface pointer to the handler instance for this app.</para>
			/// </param>
			/// <param name="pdwCookie">
			/// <para>Type: <c>DWORD*</c></para>
			/// <para>
			/// A pointer to a value that, when this method returns successfully, receives a cookie for that can be used later to unregister
			/// the handler through the Unadvise method.
			/// </para>
			/// </param>
			// https://docs.microsoft.com/en-us/windows/win32/api/shobjidl_core/nf-shobjidl_core-iframeworkinputpane-advise HRESULT Advise(
			// IUnknown *pWindow, IFrameworkInputPaneHandler *pHandler, DWORD *pdwCookie );
			void Advise([In, MarshalAs(UnmanagedType.IUnknown)] object pWindow, IFrameworkInputPaneHandler pHandler, out uint pdwCookie);

			/// <summary>
			/// Registers the app's input pane handler object to receive notifications on behalf of a window when an event triggers the
			/// input pane. This method differs from Advise in that it references its window through an <c>HWND</c>.
			/// </summary>
			/// <param name="hwnd">
			/// <para>Type: <c>HWND</c></para>
			/// <para>The handle of the window for which the handler should listen for input pane events.</para>
			/// </param>
			/// <param name="pHandler">
			/// <para>Type: <c>IFrameworkInputPaneHandler*</c></para>
			/// <para>An IFrameworkInputPaneHandler interface pointer to the handler instance for this app.</para>
			/// </param>
			/// <param name="pdwCookie">
			/// <para>Type: <c>DWORD*</c></para>
			/// <para>
			/// A pointer to a value that, when this method returns successfully, receives a cookie for that can be used later to unregister
			/// the handler through the Unadvise method.
			/// </para>
			/// </param>
			// https://docs.microsoft.com/en-us/windows/win32/api/shobjidl_core/nf-shobjidl_core-iframeworkinputpane-advisewithhwnd HRESULT
			// AdviseWithHWND( HWND hwnd, IFrameworkInputPaneHandler *pHandler, DWORD *pdwCookie );
			void AdviseWithHWND(HWND hwnd, IFrameworkInputPaneHandler pHandler, out uint pdwCookie);

			/// <summary>Unregisters an app's input pane handler object so that it no longer receives notifications.</summary>
			/// <param name="dwCookie">
			/// <para>Type: <c>DWORD</c></para>
			/// <para>A cookie that identifies the handler. This value was obtained when you registered the handler through the Advise method.</para>
			/// </param>
			// https://docs.microsoft.com/en-us/windows/win32/api/shobjidl_core/nf-shobjidl_core-iframeworkinputpane-unadvise HRESULT
			// Unadvise( DWORD dwCookie );
			void Unadvise(uint dwCookie);

			/// <summary>Gets the current location of the input pane.</summary>
			/// <returns>
			/// <para>Type: <c>RECT*</c></para>
			/// <para>
			/// A pointer to a RECT structure that, when this method returns successfully, receives the location of the input pane, in
			/// screen coordinates. If the input pane is not visible, this structure receives an empty rectangle.
			/// </para>
			/// </returns>
			// https://docs.microsoft.com/en-us/windows/win32/api/shobjidl_core/nf-shobjidl_core-iframeworkinputpane-location HRESULT
			// Location( RECT *prcInputPaneScreenLocation );
			RECT Location();
		}

		/// <summary>
		/// Enables an app to be notified when the input pane (the on-screen keyboard or handwriting panel) is being shown or hidden. This
		/// allows the app window to adjust its display so that no input areas (such as a text box) are obscured by the input pane.
		/// </summary>
		/// <remarks>
		/// <para>When to implement</para>
		/// <para>Implement this interface if your app needs to be informed when the input pane is shown or hidden, or its screen coordinates.</para>
		/// </remarks>
		// https://docs.microsoft.com/en-us/windows/win32/api/shobjidl_core/nn-shobjidl_core-iframeworkinputpanehandler
		[PInvokeData("shobjidl_core.h", MSDNShortId = "NN:shobjidl_core.IFrameworkInputPaneHandler")]
		[ComImport, Guid("226C537B-1E76-4D9E-A760-33DB29922F18"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
		public interface IFrameworkInputPaneHandler
		{
			/// <summary>
			/// Called before the input pane is shown, to allow the app window to make any necessary adjustments to its UI in response to
			/// the reduced screen space available to it. This is particularly important for input elements, such as text boxes, that are
			/// used in conjunction with the input pane.
			/// </summary>
			/// <param name="prcInputPaneScreenLocation">
			/// <para>Type: <c>RECT*</c></para>
			/// <para>A pointer to a RECT structure that supplies the screen coordinates that the input pane will occupy.</para>
			/// </param>
			/// <param name="fEnsureFocusedElementInView">
			/// <para>Type: <c>BOOL*</c></para>
			/// <para>
			/// A pointer to a value that is set to <c>true</c> if the app should attempt to keep its currently focused element (such as a
			/// text box) in view, which could require the app to move the element or rearrange its UI.
			/// </para>
			/// </param>
			/// <returns>
			/// <para>Type: <c>HRESULT</c></para>
			/// <para>If this method succeeds, it returns <c>S_OK</c>. Otherwise, it returns an <c>HRESULT</c> error code.</para>
			/// </returns>
			// https://docs.microsoft.com/en-us/windows/win32/api/shobjidl_core/nf-shobjidl_core-iframeworkinputpanehandler-showing HRESULT
			// Showing( RECT *prcInputPaneScreenLocation, BOOL fEnsureFocusedElementInView );
			[PreserveSig]
			HRESULT Showing(in RECT prcInputPaneScreenLocation, [MarshalAs(UnmanagedType.Bool)] bool fEnsureFocusedElementInView);

			/// <summary>Called when the input pane is about to leave the display.</summary>
			/// <param name="fEnsureFocusedElementInView">
			/// <para>Type: <c>BOOL*</c></para>
			/// <para>
			/// A pointer to a value that is set to <c>true</c> if the app should attempt to keep its currently focused element (such as a
			/// text box) in view, which could require the app to rearrange its UI or move the element, usually back to its layout before
			/// the input pane was shown.
			/// </para>
			/// </param>
			/// <returns>
			/// <para>Type: <c>HRESULT</c></para>
			/// <para>If this method succeeds, it returns <c>S_OK</c>. Otherwise, it returns an <c>HRESULT</c> error code.</para>
			/// </returns>
			// https://docs.microsoft.com/en-us/windows/win32/api/shobjidl_core/nf-shobjidl_core-iframeworkinputpanehandler-hiding HRESULT
			// Hiding( BOOL fEnsureFocusedElementInView );
			[PreserveSig]
			HRESULT Hiding([MarshalAs(UnmanagedType.Bool)] bool fEnsureFocusedElementInView);
		}

		/// <summary>CoClass for FrameworkInputPane</summary>
		[PInvokeData("shobjidl.h")]
		[ComImport, Guid("D5120AA3-46BA-44C5-822D-CA8092C1FC72"), ClassInterface(ClassInterfaceType.None)]
		public class FrameworkInputPane { }
	}
}