source: trunk/sources/HeuristicLab.ExtLibs/HeuristicLab.WinFormsUI/2.3.1/WinFormsUI-2.3.1/Docking/DockPanel.FocusManager.cs @ 5304

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Diagnostics.CodeAnalysis;
using System.Runtime.InteropServices;
using System.Windows.Forms;

namespace WeifenLuo.WinFormsUI.Docking {
  internal interface IContentFocusManager {
    void Activate(IDockContent content);
    void GiveUpFocus(IDockContent content);
    void AddToList(IDockContent content);
    void RemoveFromList(IDockContent content);
  }

  partial class DockPanel {
    private interface IFocusManager {
      void SuspendFocusTracking();
      void ResumeFocusTracking();
      bool IsFocusTrackingSuspended { get; }
      IDockContent ActiveContent { get; }
      DockPane ActivePane { get; }
      IDockContent ActiveDocument { get; }
      DockPane ActiveDocumentPane { get; }
    }

    private class FocusManagerImpl : Component, IContentFocusManager, IFocusManager {
      private class HookEventArgs : EventArgs {
        [SuppressMessage("Microsoft.Performance", "CA1823:AvoidUnusedPrivateFields")]
        public int HookCode;
        [SuppressMessage("Microsoft.Performance", "CA1823:AvoidUnusedPrivateFields")]
        public IntPtr wParam;
        public IntPtr lParam;
      }

      private class LocalWindowsHook : IDisposable {
        // Internal properties
        private IntPtr m_hHook = IntPtr.Zero;
        private NativeMethods.HookProc m_filterFunc = null;
        private Win32.HookType m_hookType;

        // Event delegate
        public delegate void HookEventHandler(object sender, HookEventArgs e);

        // Event: HookInvoked 
        public event HookEventHandler HookInvoked;
        protected void OnHookInvoked(HookEventArgs e) {
          if (HookInvoked != null)
            HookInvoked(this, e);
        }

        public LocalWindowsHook(Win32.HookType hook) {
          m_hookType = hook;
          m_filterFunc = new NativeMethods.HookProc(this.CoreHookProc);
        }

        // Default filter function
        public IntPtr CoreHookProc(int code, IntPtr wParam, IntPtr lParam) {
          if (code < 0)
            return NativeMethods.CallNextHookEx(m_hHook, code, wParam, lParam);

          // Let clients determine what to do
          HookEventArgs e = new HookEventArgs();
          e.HookCode = code;
          e.wParam = wParam;
          e.lParam = lParam;
          OnHookInvoked(e);

          // Yield to the next hook in the chain
          return NativeMethods.CallNextHookEx(m_hHook, code, wParam, lParam);
        }

        // Install the hook
        public void Install() {
          if (m_hHook != IntPtr.Zero)
            Uninstall();

          int threadId = NativeMethods.GetCurrentThreadId();
          m_hHook = NativeMethods.SetWindowsHookEx(m_hookType, m_filterFunc, IntPtr.Zero, threadId);
        }

        // Uninstall the hook
        public void Uninstall() {
          if (m_hHook != IntPtr.Zero) {
            NativeMethods.UnhookWindowsHookEx(m_hHook);
            m_hHook = IntPtr.Zero;
          }
        }

        ~LocalWindowsHook() {
          Dispose(false);
        }

        public void Dispose() {
          Dispose(true);
          GC.SuppressFinalize(this);
        }

        protected virtual void Dispose(bool disposing) {
          Uninstall();
        }
      }

      private LocalWindowsHook m_localWindowsHook;
      private LocalWindowsHook.HookEventHandler m_hookEventHandler;

      public FocusManagerImpl(DockPanel dockPanel) {
        m_dockPanel = dockPanel;
        m_localWindowsHook = new LocalWindowsHook(Win32.HookType.WH_CALLWNDPROCRET);
        m_hookEventHandler = new LocalWindowsHook.HookEventHandler(HookEventHandler);
        m_localWindowsHook.HookInvoked += m_hookEventHandler;
        m_localWindowsHook.Install();
      }

      private DockPanel m_dockPanel;
      public DockPanel DockPanel {
        get { return m_dockPanel; }
      }

      private bool m_disposed = false;
      protected override void Dispose(bool disposing) {
        lock (this) {
          if (!m_disposed && disposing) {
            m_localWindowsHook.Dispose();
            m_disposed = true;
          }

          base.Dispose(disposing);
        }
      }

      private IDockContent m_contentActivating = null;
      private IDockContent ContentActivating {
        get { return m_contentActivating; }
        set { m_contentActivating = value; }
      }

      public void Activate(IDockContent content) {
        if (IsFocusTrackingSuspended) {
          ContentActivating = content;
          return;
        }

        if (content == null)
          return;
        DockContentHandler handler = content.DockHandler;
        if (handler.Form.IsDisposed)
          return; // Should not reach here, but better than throwing an exception
        if (ContentContains(content, handler.ActiveWindowHandle))
          NativeMethods.SetFocus(handler.ActiveWindowHandle);
        if (!handler.Form.ContainsFocus) {
          if (!handler.Form.SelectNextControl(handler.Form.ActiveControl, true, true, true, true))
            // Since DockContent Form is not selectalbe, use Win32 SetFocus instead
            NativeMethods.SetFocus(handler.Form.Handle);
        }
      }

      private List<IDockContent> m_listContent = new List<IDockContent>();
      private List<IDockContent> ListContent {
        get { return m_listContent; }
      }
      public void AddToList(IDockContent content) {
        if (ListContent.Contains(content) || IsInActiveList(content))
          return;

        ListContent.Add(content);
      }

      public void RemoveFromList(IDockContent content) {
        if (IsInActiveList(content))
          RemoveFromActiveList(content);
        if (ListContent.Contains(content))
          ListContent.Remove(content);
      }

      private IDockContent m_lastActiveContent = null;
      private IDockContent LastActiveContent {
        get { return m_lastActiveContent; }
        set { m_lastActiveContent = value; }
      }

      private bool IsInActiveList(IDockContent content) {
        return !(content.DockHandler.NextActive == null && LastActiveContent != content);
      }

      private void AddLastToActiveList(IDockContent content) {
        IDockContent last = LastActiveContent;
        if (last == content)
          return;

        DockContentHandler handler = content.DockHandler;

        if (IsInActiveList(content))
          RemoveFromActiveList(content);

        handler.PreviousActive = last;
        handler.NextActive = null;
        LastActiveContent = content;
        if (last != null)
          last.DockHandler.NextActive = LastActiveContent;
      }

      private void RemoveFromActiveList(IDockContent content) {
        if (LastActiveContent == content)
          LastActiveContent = content.DockHandler.PreviousActive;

        IDockContent prev = content.DockHandler.PreviousActive;
        IDockContent next = content.DockHandler.NextActive;
        if (prev != null)
          prev.DockHandler.NextActive = next;
        if (next != null)
          next.DockHandler.PreviousActive = prev;

        content.DockHandler.PreviousActive = null;
        content.DockHandler.NextActive = null;
      }

      public void GiveUpFocus(IDockContent content) {
        DockContentHandler handler = content.DockHandler;
        if (!handler.Form.ContainsFocus)
          return;

        if (IsFocusTrackingSuspended)
          DockPanel.DummyControl.Focus();

        if (LastActiveContent == content) {
          IDockContent prev = handler.PreviousActive;
          if (prev != null)
            Activate(prev);
          else if (ListContent.Count > 0)
            Activate(ListContent[ListContent.Count - 1]);
        } else if (LastActiveContent != null)
          Activate(LastActiveContent);
        else if (ListContent.Count > 0)
          Activate(ListContent[ListContent.Count - 1]);
      }

      private static bool ContentContains(IDockContent content, IntPtr hWnd) {
        Control control = Control.FromChildHandle(hWnd);
        for (Control parent = control; parent != null; parent = parent.Parent)
          if (parent == content.DockHandler.Form)
            return true;

        return false;
      }

      private int m_countSuspendFocusTracking = 0;
      public void SuspendFocusTracking() {
        m_countSuspendFocusTracking++;
        m_localWindowsHook.HookInvoked -= m_hookEventHandler;
      }

      public void ResumeFocusTracking() {
        if (m_countSuspendFocusTracking > 0)
          m_countSuspendFocusTracking--;

        if (m_countSuspendFocusTracking == 0) {
          if (ContentActivating != null) {
            Activate(ContentActivating);
            ContentActivating = null;
          }
          m_localWindowsHook.HookInvoked += m_hookEventHandler;
          if (!InRefreshActiveWindow)
            RefreshActiveWindow();
        }
      }

      public bool IsFocusTrackingSuspended {
        get { return m_countSuspendFocusTracking != 0; }
      }

      // Windows hook event handler
      private void HookEventHandler(object sender, HookEventArgs e) {
        Win32.Msgs msg = (Win32.Msgs)Marshal.ReadInt32(e.lParam, IntPtr.Size * 3);

        if (msg == Win32.Msgs.WM_KILLFOCUS) {
          IntPtr wParam = Marshal.ReadIntPtr(e.lParam, IntPtr.Size * 2);
          DockPane pane = GetPaneFromHandle(wParam);
          if (pane == null)
            RefreshActiveWindow();
        } else if (msg == Win32.Msgs.WM_SETFOCUS)
          RefreshActiveWindow();
      }

      private DockPane GetPaneFromHandle(IntPtr hWnd) {
        Control control = Control.FromChildHandle(hWnd);

        IDockContent content = null;
        DockPane pane = null;
        for (; control != null; control = control.Parent) {
          content = control as IDockContent;
          if (content != null)
            content.DockHandler.ActiveWindowHandle = hWnd;

          if (content != null && content.DockHandler.DockPanel == DockPanel)
            return content.DockHandler.Pane;

          pane = control as DockPane;
          if (pane != null && pane.DockPanel == DockPanel)
            break;
        }

        return pane;
      }

      private bool m_inRefreshActiveWindow = false;
      private bool InRefreshActiveWindow {
        get { return m_inRefreshActiveWindow; }
      }

      private void RefreshActiveWindow() {
        SuspendFocusTracking();
        m_inRefreshActiveWindow = true;

        DockPane oldActivePane = ActivePane;
        IDockContent oldActiveContent = ActiveContent;
        IDockContent oldActiveDocument = ActiveDocument;

        SetActivePane();
        SetActiveContent();
        SetActiveDocumentPane();
        SetActiveDocument();
        DockPanel.AutoHideWindow.RefreshActivePane();

        ResumeFocusTracking();
        m_inRefreshActiveWindow = false;

        if (oldActiveContent != ActiveContent)
          DockPanel.OnActiveContentChanged(EventArgs.Empty);
        if (oldActiveDocument != ActiveDocument)
          DockPanel.OnActiveDocumentChanged(EventArgs.Empty);
        if (oldActivePane != ActivePane)
          DockPanel.OnActivePaneChanged(EventArgs.Empty);
      }

      private DockPane m_activePane = null;
      public DockPane ActivePane {
        get { return m_activePane; }
      }

      private void SetActivePane() {
        DockPane value = GetPaneFromHandle(NativeMethods.GetFocus());
        if (m_activePane == value)
          return;

        if (m_activePane != null)
          m_activePane.SetIsActivated(false);

        m_activePane = value;

        if (m_activePane != null)
          m_activePane.SetIsActivated(true);
      }

      private IDockContent m_activeContent = null;
      public IDockContent ActiveContent {
        get { return m_activeContent; }
      }

      internal void SetActiveContent() {
        IDockContent value = ActivePane == null ? null : ActivePane.ActiveContent;

        if (m_activeContent == value)
          return;

        if (m_activeContent != null)
          m_activeContent.DockHandler.IsActivated = false;

        m_activeContent = value;

        if (m_activeContent != null) {
          m_activeContent.DockHandler.IsActivated = true;
          if (!DockHelper.IsDockStateAutoHide((m_activeContent.DockHandler.DockState)))
            AddLastToActiveList(m_activeContent);
        }
      }

      private DockPane m_activeDocumentPane = null;
      public DockPane ActiveDocumentPane {
        get { return m_activeDocumentPane; }
      }

      private void SetActiveDocumentPane() {
        DockPane value = null;

        if (ActivePane != null && ActivePane.DockState == DockState.Document)
          value = ActivePane;

        if (value == null && DockPanel.DockWindows != null) {
          if (ActiveDocumentPane == null)
            value = DockPanel.DockWindows[DockState.Document].DefaultPane;
          else if (ActiveDocumentPane.DockPanel != DockPanel || ActiveDocumentPane.DockState != DockState.Document)
            value = DockPanel.DockWindows[DockState.Document].DefaultPane;
          else
            value = ActiveDocumentPane;
        }

        if (m_activeDocumentPane == value)
          return;

        if (m_activeDocumentPane != null)
          m_activeDocumentPane.SetIsActiveDocumentPane(false);

        m_activeDocumentPane = value;

        if (m_activeDocumentPane != null)
          m_activeDocumentPane.SetIsActiveDocumentPane(true);
      }

      private IDockContent m_activeDocument = null;
      public IDockContent ActiveDocument {
        get { return m_activeDocument; }
      }

      private void SetActiveDocument() {
        IDockContent value = ActiveDocumentPane == null ? null : ActiveDocumentPane.ActiveContent;

        if (m_activeDocument == value)
          return;

        m_activeDocument = value;
      }
    }

    private IFocusManager FocusManager {
      get { return m_focusManager; }
    }

    internal IContentFocusManager ContentFocusManager {
      get { return m_focusManager; }
    }

    internal void SaveFocus() {
      DummyControl.Focus();
    }

    [Browsable(false)]
    public IDockContent ActiveContent {
      get { return FocusManager.ActiveContent; }
    }

    [Browsable(false)]
    public DockPane ActivePane {
      get { return FocusManager.ActivePane; }
    }

    [Browsable(false)]
    public IDockContent ActiveDocument {
      get { return FocusManager.ActiveDocument; }
    }

    [Browsable(false)]
    public DockPane ActiveDocumentPane {
      get { return FocusManager.ActiveDocumentPane; }
    }

    private static readonly object ActiveDocumentChangedEvent = new object();
    [LocalizedCategory("Category_PropertyChanged")]
    [LocalizedDescription("DockPanel_ActiveDocumentChanged_Description")]
    public event EventHandler ActiveDocumentChanged {
      add { Events.AddHandler(ActiveDocumentChangedEvent, value); }
      remove { Events.RemoveHandler(ActiveDocumentChangedEvent, value); }
    }
    protected virtual void OnActiveDocumentChanged(EventArgs e) {
      EventHandler handler = (EventHandler)Events[ActiveDocumentChangedEvent];
      if (handler != null)
        handler(this, e);
    }

    private static readonly object ActiveContentChangedEvent = new object();
    [LocalizedCategory("Category_PropertyChanged")]
    [LocalizedDescription("DockPanel_ActiveContentChanged_Description")]
    public event EventHandler ActiveContentChanged {
      add { Events.AddHandler(ActiveContentChangedEvent, value); }
      remove { Events.RemoveHandler(ActiveContentChangedEvent, value); }
    }
    protected void OnActiveContentChanged(EventArgs e) {
      EventHandler handler = (EventHandler)Events[ActiveContentChangedEvent];
      if (handler != null)
        handler(this, e);
    }

    private static readonly object ActivePaneChangedEvent = new object();
    [LocalizedCategory("Category_PropertyChanged")]
    [LocalizedDescription("DockPanel_ActivePaneChanged_Description")]
    public event EventHandler ActivePaneChanged {
      add { Events.AddHandler(ActivePaneChangedEvent, value); }
      remove { Events.RemoveHandler(ActivePaneChangedEvent, value); }
    }
    protected virtual void OnActivePaneChanged(EventArgs e) {
      EventHandler handler = (EventHandler)Events[ActivePaneChangedEvent];
      if (handler != null)
        handler(this, e);
    }
  }
}