ShareX/ShareX.UploadersLib/FTPClient/ListViewEx.cs

#region License Information (GPL v3)

/*
    ShareX - A program that allows you to take screenshots and share any file type
    Copyright (c) 2007-2018 ShareX Team

    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License
    as published by the Free Software Foundation; either version 2
    of the License, or (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

    Optionally you can also view the license at <http://www.gnu.org/licenses/>.
*/

#endregion License Information (GPL v3)

using System;
using System.ComponentModel;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Windows.Forms;

namespace ShareX.UploadersLib
{
    ///	<summary>
    ///	Inherited ListView to allow in-place editing of subitems
    ///	</summary>
    public class ListViewEx : ListView
    {
        #region Interop structs, imports and constants

        /// <summary>
        /// MessageHeader for WM_NOTIFY
        /// </summary>
        [StructLayout(LayoutKind.Sequential)]
        private struct NMHDR
        {
            public IntPtr hwndFrom;
            public Int32 idFrom;
            public Int32 code;
        }

        [DllImport("user32.dll")]
        private static extern IntPtr SendMessage(IntPtr hWnd, int msg, IntPtr wPar, IntPtr lPar);

        [DllImport("user32.dll", CharSet = CharSet.Ansi)]
        private static extern IntPtr SendMessage(IntPtr hWnd, int msg, int len, ref int[] order);

        // ListView messages
        private const int LVM_FIRST = 0x1000;
        private const int LVM_GETCOLUMNORDERARRAY = LVM_FIRST + 59;

        // Windows Messages that will abort editing
        private const int WM_HSCROLL = 0x114;
        private const int WM_VSCROLL = 0x115;
        private const int WM_SIZE = 0x05;
        private const int WM_NOTIFY = 0x4E;

        private const int HDN_FIRST = -300;
        private const int HDN_BEGINDRAG = HDN_FIRST - 10;
        private const int HDN_ITEMCHANGINGA = HDN_FIRST - 0;
        private const int HDN_ITEMCHANGINGW = HDN_FIRST - 20;

        #endregion Interop structs, imports and constants

        ///	<summary>
        ///	Required designer variable.
        ///	</summary>
        private Container components;

        public event SubItemEventHandler SubItemClicked;
        public event SubItemEventHandler SubItemBeginEditing;
        public event SubItemEndEditingEventHandler SubItemEndEditing;

        public ListViewEx()
        {
            DoubleClickActivation = false;
            // This	call is	required by	the	Windows.Forms Form Designer.
            InitializeComponent();

            FullRowSelect = true;
            View = View.Details;
            AllowColumnReorder = true;
        }

        ///	<summary>
        ///	Clean up any resources being used.
        ///	</summary>
        protected override void Dispose(bool disposing)
        {
            if (disposing)
            {
                if (components != null)
                    components.Dispose();
            }
            base.Dispose(disposing);
        }

        #region Component	Designer generated code

        ///	<summary>
        ///	Required method	for	Designer support - do not modify
        ///	the	contents of	this method	with the code editor.
        ///	</summary>
        private void InitializeComponent()
        {
            components = new Container();
        }

        #endregion Component	Designer generated code

        /// <summary>
        /// Is a double click required to start editing a cell?
        /// </summary>
        public bool DoubleClickActivation { get; set; }

        /// <summary>
        /// Retrieve the order in which columns appear
        /// </summary>
        /// <returns>Current display order of column indices</returns>
        public int[] GetColumnOrder()
        {
            IntPtr lPar = Marshal.AllocHGlobal(Marshal.SizeOf(typeof(int)) * Columns.Count);

            IntPtr res = SendMessage(Handle, LVM_GETCOLUMNORDERARRAY, new IntPtr(Columns.Count), lPar);
            if (res.ToInt32() == 0) // Something went wrong
            {
                Marshal.FreeHGlobal(lPar);
                return null;
            }

            int[] order = new int[Columns.Count];
            Marshal.Copy(lPar, order, 0, Columns.Count);

            Marshal.FreeHGlobal(lPar);

            return order;
        }

        /// <summary>
        /// Find ListViewItem and SubItem Index at position (x,y)
        /// </summary>
        /// <param name="x">relative to ListView</param>
        /// <param name="y">relative to ListView</param>
        /// <param name="item">Item at position (x,y)</param>
        /// <returns>SubItem index</returns>
        public int GetSubItemAt(int x, int y, out ListViewItem item)
        {
            item = GetItemAt(x, y);

            if (item != null)
            {
                int[] order = GetColumnOrder();

                Rectangle lviBounds = item.GetBounds(ItemBoundsPortion.Entire);
                int subItemX = lviBounds.Left;
                foreach (int t in order)
                {
                    ColumnHeader h = Columns[t];
                    if (x < subItemX + h.Width)
                    {
                        return h.Index;
                    }
                    subItemX += h.Width;
                }
            }

            return -1;
        }

        /// <summary>
        /// Get bounds for a SubItem
        /// </summary>
        /// <param name="Item">Target ListViewItem</param>
        /// <param name="SubItem">Target SubItem index</param>
        /// <returns>Bounds of SubItem (relative to ListView)</returns>
        public Rectangle GetSubItemBounds(ListViewItem Item, int SubItem)
        {
            int[] order = GetColumnOrder();

            if (SubItem >= order.Length)
                throw new IndexOutOfRangeException("SubItem " + SubItem + " out of range");

            if (Item == null)
                throw new ArgumentNullException("Item");

            Rectangle lviBounds = Item.GetBounds(ItemBoundsPortion.Entire);
            int subItemX = lviBounds.Left;

            ColumnHeader col;
            int i;
            for (i = 0; i < order.Length; i++)
            {
                col = Columns[order[i]];
                if (col.Index == SubItem)
                    break;
                subItemX += col.Width;
            }
            Rectangle subItemRect = new Rectangle(subItemX, lviBounds.Top, Columns[order[i]].Width, lviBounds.Height);
            return subItemRect;
        }

        protected override void WndProc(ref Message msg)
        {
            switch (msg.Msg)
            {
                // Look	for	WM_VSCROLL,WM_HSCROLL or WM_SIZE messages.
                case WM_VSCROLL:
                case WM_HSCROLL:
                case WM_SIZE:
                    EndEditing(false);
                    break;
                case WM_NOTIFY:
                    // Look for WM_NOTIFY of events that might also change the
                    // editor's position/size: Column reordering or resizing
                    NMHDR h = (NMHDR)Marshal.PtrToStructure(msg.LParam, typeof(NMHDR));
                    if (h.code == HDN_BEGINDRAG ||
                        h.code == HDN_ITEMCHANGINGA ||
                        h.code == HDN_ITEMCHANGINGW)
                        EndEditing(false);
                    break;
            }

            base.WndProc(ref msg);
        }

        #region Initialize editing depending of DoubleClickActivation property

        protected override void OnMouseUp(MouseEventArgs e)
        {
            base.OnMouseUp(e);

            if (DoubleClickActivation)
            {
                return;
            }

            EditSubitemAt(new Point(e.X, e.Y));
        }

        protected override void OnDoubleClick(EventArgs e)
        {
            base.OnDoubleClick(e);

            if (!DoubleClickActivation)
            {
                return;
            }

            Point pt = PointToClient(Cursor.Position);

            EditSubitemAt(pt);
        }

        ///<summary>
        /// Fire SubItemClicked
        ///</summary>
        ///<param name="p">Point of click/doubleclick</param>
        private void EditSubitemAt(Point p)
        {
            ListViewItem item;
            int idx = GetSubItemAt(p.X, p.Y, out item);
            if (idx >= 0)
            {
                OnSubItemClicked(new SubItemEventArgs(item, idx));
            }
        }

        #endregion Initialize editing depending of DoubleClickActivation property

        #region In-place editing functions

        // The control performing the actual editing
        private Control _editingControl;
        // The LVI being edited
        private ListViewItem _editItem;
        // The SubItem being edited
        private int _editSubItem;

        protected void OnSubItemBeginEditing(SubItemEventArgs e)
        {
            if (SubItemBeginEditing != null)
                SubItemBeginEditing(this, e);
        }

        protected void OnSubItemEndEditing(SubItemEndEditingEventArgs e)
        {
            if (SubItemEndEditing != null)
                SubItemEndEditing(this, e);
        }

        protected void OnSubItemClicked(SubItemEventArgs e)
        {
            if (SubItemClicked != null)
                SubItemClicked(this, e);
        }

        /// <summary>
        /// Begin in-place editing of given cell
        /// </summary>
        /// <param name="c">Control used as cell editor</param>
        /// <param name="Item">ListViewItem to edit</param>
        /// <param name="SubItem">SubItem index to edit</param>
        public void StartEditing(Control c, ListViewItem Item, int SubItem)
        {
            OnSubItemBeginEditing(new SubItemEventArgs(Item, SubItem));

            Rectangle rcSubItem = GetSubItemBounds(Item, SubItem);

            if (rcSubItem.X < 0)
            {
                // Left edge of SubItem not visible - adjust rectangle position and width
                rcSubItem.Width += rcSubItem.X;
                rcSubItem.X = 0;
            }
            if (rcSubItem.X + rcSubItem.Width > Width)
            {
                // Right edge of SubItem not visible - adjust rectangle width
                rcSubItem.Width = Width - rcSubItem.Left;
            }

            // Subitem bounds are relative to the location of the ListView!
            rcSubItem.Offset(Left, Top);

            // In case the editing control and the listview are on different parents,
            // account for different origins
            Point origin = new Point(0, 0);
            Point lvOrigin = Parent.PointToScreen(origin);
            Point ctlOrigin = c.Parent.PointToScreen(origin);

            rcSubItem.Offset(lvOrigin.X - ctlOrigin.X, lvOrigin.Y - ctlOrigin.Y);

            // Position and show editor
            c.Bounds = rcSubItem;
            c.Text = Item.SubItems[SubItem].Text;
            c.Visible = true;
            c.BringToFront();
            c.Focus();

            _editingControl = c;
            _editingControl.Leave += _editControl_Leave;
            _editingControl.KeyPress += _editControl_KeyPress;

            _editItem = Item;
            _editSubItem = SubItem;
        }

        private void _editControl_Leave(object sender, EventArgs e)
        {
            // cell editor losing focus
            EndEditing(true);
        }

        private void _editControl_KeyPress(object sender, KeyPressEventArgs e)
        {
            switch (e.KeyChar)
            {
                case (char)(int)Keys.Escape:
                    {
                        EndEditing(false);
                        break;
                    }

                case (char)(int)Keys.Enter:
                    {
                        EndEditing(true);
                        break;
                    }
            }
        }

        /// <summary>
        /// Accept or discard current value of cell editor control
        /// </summary>
        /// <param name="AcceptChanges">Use the _editingControl's Text as new SubItem text or discard changes?</param>
        public void EndEditing(bool AcceptChanges)
        {
            if (_editingControl == null)
                return;

            SubItemEndEditingEventArgs e = new SubItemEndEditingEventArgs(
                _editItem, // The item being edited
                _editSubItem, // The subitem index being edited
                AcceptChanges ?
                    _editingControl.Text : // Use editControl text if changes are accepted
                    _editItem.SubItems[_editSubItem].Text, // or the original subitem's text, if changes are discarded
                !AcceptChanges // Cancel?
                );

            OnSubItemEndEditing(e);

            if (!string.IsNullOrEmpty(e.DisplayText))
            {
                _editItem.SubItems[_editSubItem].Text = e.DisplayText;
            }

            _editingControl.Leave -= _editControl_Leave;
            _editingControl.KeyPress -= _editControl_KeyPress;

            _editingControl.Visible = false;

            _editingControl = null;
            _editItem = null;
            _editSubItem = -1;
        }

        #endregion In-place editing functions
    }

    /// <summary>
    /// Event Handler for SubItem events
    /// </summary>
    public delegate void SubItemEventHandler(object sender, SubItemEventArgs e);

    /// <summary>
    /// Event Handler for SubItemEndEditing events
    /// </summary>
    public delegate void SubItemEndEditingEventHandler(object sender, SubItemEndEditingEventArgs e);

    /// <summary>
    /// Event Args for SubItemClicked event
    /// </summary>
    public class SubItemEventArgs : EventArgs
    {
        public SubItemEventArgs(ListViewItem item, int subItem)
        {
            _subItemIndex = subItem;
            _item = item;
        }

        private int _subItemIndex = -1;
        private ListViewItem _item;

        public int SubItem
        {
            get
            {
                return _subItemIndex;
            }
        }

        public ListViewItem Item
        {
            get
            {
                return _item;
            }
        }
    }

    /// <summary>
    /// Event Args for SubItemEndEditingClicked event
    /// </summary>
    public class SubItemEndEditingEventArgs : SubItemEventArgs
    {
        private string _text = "";
        private bool _cancel = true;

        public SubItemEndEditingEventArgs(ListViewItem item, int subItem, string display, bool cancel) :
            base(item, subItem)
        {
            _text = display;
            _cancel = cancel;
        }

        public string DisplayText
        {
            get
            {
                return _text;
            }
            set
            {
                _text = value;
            }
        }

        public bool Cancel
        {
            get
            {
                return _cancel;
            }
            set
            {
                _cancel = value;
            }
        }
    }
}