Audio Book Player

using System;
using System.Collections.Generic;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using System.Collections;
using System.Threading;
using System.IO;
using System.Reflection;
using Microsoft.Win32;

namespace abPlayer
{
    public partial class frmPlayer : Form
    {
        // API used
        [DllImport("coredll.dll")]
        public static extern IntPtr GetDC(IntPtr hWnd);
        [DllImport("coredll.dll")]
        public static extern int ReleaseDC(IntPtr hWnd, IntPtr hDC);
        // skin related constants
        private const String SKIN_DIR = "\\skins";
        private const String NO_SKIN = "None";
        private String SkinDir;
        // default backlight timeout
        private const int BACKLIGHT_TIMEOUT = 10;
        // key press constants
        const int TIME_CHANGE = 10;
        const int VOLUME_CHANGE = 5;
        // class that encapsulates various calls to win API
        private cASUS639DeviceSpecifics DeviceSpecifics = null;
        // form used to manage and maintain books (playlists)
        private frmLibrary Library = null;
        // form used to manage book properties
        private frmProps Props = null;
        // the class that manages the windows media player access
        private cPlayer Player = null;
        // In order to prevent auto power off 
        // a set of API needs to be called periodically (less than the auto
        // power off timeout set in the device. So - 
        // we keep the interval desired (Threshold) and a time stamp indicating
        // when the reset was last performed
        private long KeepPowerThreshold = 30;
        private DateTime KeepPowerTimeStamp = DateTime.Now;
        // text color of the display and the forecolor of the controls change
        // to reflect battery state: charging = white, good = yellow
        // medium = orange, critical = red.
        private Color TextColor = Color.White;
        // since volume is saved as a book property and is set as a book is being
        // played, we keep the volume level at entry time and resores it on exit.
        private int SaveEntryVolume = 0;
        // same for backlight timeout
        private int SaveEntryBacklight = 0;
        // sleep function data
        private DateTime SleepTime = DateTime.Now;
        private bool SleepActive = false;
        private int[] SleepIntervals = { 15, 30, 60, 90, 120 };
        // media transition goes through several statuses
        // to avoid intermediate status displays, status paint is not done
        // in real time but rather on the next timer tick
        private bool NeedStatusPaint = false;
        // if no media is being played timeline location does't change
        // to avoid excessive and unnecessary screen paint and persistancy saves
        // we only do it if location actually changed
        private int LastLocationSaved = -1;

        public frmPlayer()
        {
            InitializeComponent();
            // this will catch any object and subsequent object creation error (as
            // all 7 major objects - 4 forms and 3 classes are instantiated here).
            // most common reasons: low memory and low battery
            try
            {
                // various non managed API calls
                DeviceSpecifics = new cASUS639DeviceSpecifics();
                // forms used to manage and maintain books & book properties
                Library = new frmLibrary();
                // the class that manages the windows media player access
                Player = new cPlayer();
                // form to manage book properties
                Props = new frmProps(Library, Player, DeviceSpecifics);
            }
            catch (Exception e)
            {
                MessageBox.Show("Failed to Initialize Objects - " +
                    e.Message, "Fatal Error");
                Close();
                return;
            }
            // align buttons
            picDark.Left = picLight.Left = 2;
            // prepare paint resources
            apiDC = GetDC(this.Handle);
            if (apiDC == IntPtr.Zero)
            {
                MessageBox.Show("Failed to Initialize GDI Resource", "Fatal Error");
                Close();
                return;
            }
            try
            {
                screenGraphics = Graphics.FromHdc(apiDC);
                fgBMP = new Bitmap(Width, pnlBottom.Top - pnlTop.Height);
                fgGraphics = Graphics.FromImage(fgBMP);
                bgBMP = new Bitmap(Width, pnlBottom.Top - pnlTop.Height);
                bgGraphics = Graphics.FromImage(bgBMP);
            }
            catch
            {
                MessageBox.Show("Failed to Initialize Graphics Resource", "Fatal Error");
                Close();
                return;
            }
            todFont = new Font(this.Font.Name, TOD_FONT_SIZE, FontStyle.Bold);
            // enumerate existing skins and mark active one
            SkinDir = Path.GetDirectoryName(Assembly.GetExecutingAssembly().GetName().CodeBase) +
                SKIN_DIR;
            String sk = Library.BookStore.Skin;
            try
            {
                foreach (DirectoryInfo dir in new DirectoryInfo(SkinDir).GetDirectories())
                {
                    MenuItem mnu = new MenuItem();
                    mnu.Text = dir.Name;
                    mnu.Checked = (mnu.Text.ToUpper() == sk.ToUpper());
                    mnu.Click += new EventHandler(mnuSkin_Click);
                    mnuSkins.MenuItems.Add(mnu);
                }
            }
            catch
            {
                MessageBox.Show("Failed to Find Skins Dir", "Error");
            }
            MenuItem mni = new MenuItem();
            mni.Text = "-";
            mnuSkins.MenuItems.Add(mni);
            mni = new MenuItem();
            mni.Text = NO_SKIN;
            mni.Checked = (mni.Text.ToUpper() == sk.ToUpper());
            mni.Click += new EventHandler(mnuSkin_Click);
            mnuSkins.MenuItems.Add(mni);
            //Load Active skin
            LoadSkin(sk);
            // ser print related sizes
            textHeight = (int)fgGraphics.MeasureString("Z", this.Font).Height;
            // time till sleep display
            lblSleep.Text = "";
            // set backlight timeout 
            SaveEntryBacklight = DeviceSpecifics.BacklightTimeout;
            if (BACKLIGHT_TIMEOUT != SaveEntryBacklight)
                DeviceSpecifics.BacklightTimeout = BACKLIGHT_TIMEOUT;
            // initialize event handlers
            Player.PlayItemChanged += new PlayItemChangedEventHandler(Player_PlayItemChanged);
            Player.StatusChanged += new StatusChangedEventHandler(Player_StatusChanged);
            SaveEntryVolume = DeviceSpecifics.Volume;
            // get device screensave timeout 
            KeepPowerThreshold = DeviceSpecifics.PowerOffThreshold;
            // if we have an active book - go load it
            if ((Library.BookStore.ActiveBookName.Length > 0) &&
                (Library.BookStore.GetBookFileCount("") > 0))
            {
                // set volume
                DeviceSpecifics.Volume = Library.BookStore.GetBookProperty(eBookProperty.VOLUME, "");
                // Load playlist, restore bookmark and pause
                Player.Playlist(Library.BookStore.GetBookFiles(""),
                                Library.BookStore.GetBookProperty(eBookProperty.BOOKMARK_ENTRY, ""),
                                Library.BookStore.GetBookProperty(eBookProperty.BOOKMARK_LOCATION, ""),
                                (Library.BookStore.GetBookProperty(eBookProperty.SHUFFLE, "") != 0));
                // take stock of current location
                PaintLocation();
                // force garbage collection here to dispose of all obsolete objects 
                // to prevent gc to kick in when it may disturb the playing
                GC.Collect();
                // signal ready to play
                DeviceSpecifics.Beep();
            }
            tmr.Enabled = true;
        }
        // skin menu clicked
        void mnuSkin_Click(object sender, EventArgs e)
        {
            if (((MenuItem)sender).Checked) return;
            foreach (MenuItem mnu in mnuSkins.MenuItems)
                mnu.Checked = (((MenuItem)sender) == mnu);
            Library.BookStore.Skin = ((MenuItem)sender).Text;
            LoadSkin(((MenuItem)sender).Text);
            PaintScreen();
        }
        // load 5 forms skins
        void LoadSkin(String skin)
        {
            ApplySkin(skin, this);
            ApplySkin(skin, Library);
            ApplySkin(skin, Library.FileSelector);
            ApplySkin(skin, Props);
            ApplySkin(skin, Props.MediaProps);
            // set text color of sleep label to picture color
            if (skin == NO_SKIN)
                lblSleep.ForeColor = TextColor;
            else
            {
                try
                {
                    Bitmap bmp = new Bitmap(picSleep.Image);
                    for (int i = 0; i < picSleep.Width; i++)
                        for (int j = 0; j < picSleep.Height; j++)
                        {
                            int c = bmp.GetPixel(i, j).ToArgb();
                            if (((c & 0x00FF0000) > (0x00FF0000 / 2)) ||
                            ((c & 0x0000FF00) > (0x0000FF00 / 2)) ||
                            ((c & 0x000000FF) > (0x000000FF / 2)))
                            {
                                lblSleep.ForeColor = bmp.GetPixel(i, j);
                                bmp.Dispose();
                                return;
                            }
                        }
                }
                catch { }
            }
        }
        // find all picturebox controls and load image
        void ApplySkin(String skin, Control ctrl)
        {
            foreach (Control item in ctrl.Controls)
                if (item.GetType() == typeof(PictureBox))
                {
                    if (((PictureBox)item).Tag != null)
                    {
                        ((PictureBox)item).Paint += Library.FileSelector.Pic_Paint;
                        ((PictureBox)item).Image = null;
                        // load a picture
                        if (skin != NO_SKIN)
                        {
                            try
                            {
                                String[] file = Directory.GetFiles(SkinDir + "\\" + skin, (String)((PictureBox)item).Tag + ".*");
                                if (file.Length > 0)
                                    ((PictureBox)item).Image = new Bitmap(file[0]);
                            }
                            catch { }
                        }
                    }
                }
                else
                    ApplySkin(skin, item);
        }
        // monitor status change and show it
        // do it on next timer 1 second tick so if status is changed rapidly
        // (as in playlist loading) I don't show all intermediate statuses
        void Player_StatusChanged(object sender, StatusChangedEventArgs e)
        {
            NeedStatusPaint = true;
        }
        // player or user changed the active file. Commit it to persistant storage
        void Player_PlayItemChanged(object sender, PlayItemChangedEventArgs e)
        {
            if (e.ItemIndex > -1)
                Library.BookStore.SetBookProperty(eBookProperty.BOOKMARK_ENTRY, e.ItemIndex, "");
            PaintScreen();
        }
        // this is a timer (1 second) based event so we can reflect 
        // the new timeline marker visually and commit it to persistant storage
        // we also do all time based housekeeping
        private void tmr_Tick(object sender, EventArgs e)
        {
            if ((Player.Duration != -1) &&
                (Player.Location != -1) &&
                (LastLocationSaved != Player.Location))
            {
                LastLocationSaved = Player.Location;
                PaintLocation();
                Library.BookStore.SetBookProperty(eBookProperty.BOOKMARK_LOCATION,
                    Player.Location, "");
            }
            if (NeedStatusPaint)
            {
                PaintStatus(Player.StatusString);
                NeedStatusPaint = false;
            }
            DateTime now = DateTime.Now;
            // check if time since last reset has reached the threshold
            if ((now - KeepPowerTimeStamp).TotalSeconds >= KeepPowerThreshold)
            {
                // yes - rewind timestamp and paint time and battery state
                KeepPowerTimeStamp = now;
                DeviceSpecifics.PreventAutoPowerOff();
            }
            // update tod display
            if(now.Second == 0)
                PaintBatteryVolAndTOD();
            // flying text
            if ((Player.PlaylistCount > 0) &&
                (flyingTextCount > 0))
                PaintFlyingText();
            // handle sleep
            if (SleepActive)
            {
                DrawSleepTime();
                if (SleepTime <= DateTime.Now)
                {
                    ReleaseResources();
                    // shutdown
                    DeviceSpecifics.PowerOff();
                    Close();
                    return;
                }
            }
        }
        // click
        private void frmPlayer_Click(object sender, EventArgs e)
        {
            SwitchState();
        }
        // exit program after stopping media player
        private void picExit_Click(object sender, EventArgs e)
        {
            Library.FileSelector.FlashControl((Control)sender);
            ReleaseResources();
            Close();
        }
        // release resources. close all
        void ReleaseResources()
        {
            try
            {
                tmr.Enabled = false;
                Player.StopAndClear();
                if (fgBMP != null)
                    fgBMP.Dispose();
                if (fgGraphics != null)
                    fgGraphics.Dispose();
                if (bgBMP != null)
                    bgBMP.Dispose();
                if (bgGraphics != null)
                    bgGraphics.Dispose();
                if (screenGraphics != null)
                    screenGraphics.Dispose();
                if (apiDC != IntPtr.Zero)
                    ReleaseDC(this.Handle, apiDC);
                Player.Dispose();
            }
            catch { }
            finally
            {
                DeviceSpecifics.Volume = SaveEntryVolume;
                DeviceSpecifics.BacklightTimeout = SaveEntryBacklight;
            }
        }
        // light on
        private void picLight_Click(object sender, EventArgs e)
        {
            Library.FileSelector.FlashControl((Control)sender);
            picLight.Visible = !picLight.Visible;
            picDark.Visible = !picDark.Visible;
            DeviceSpecifics.BacklightTimeout = BACKLIGHT_TIMEOUT;
        }
        // light off
        private void picDark_Click(object sender, EventArgs e)
        {
            Library.FileSelector.FlashControl((Control)sender);
            picLight.Visible = !picLight.Visible;
            picDark.Visible = !picDark.Visible;
            DeviceSpecifics.BacklightTimeout = 0;
        }
        // play button pressed
        private void picPlay_Click(object sender, EventArgs e)
        {
            // if we are not already playing and there's a playlist - do it
            Library.FileSelector.FlashControl((Control)sender);
            if((Player.Status != ePlayerStatus.PLAYING) && (Player.PlaylistCount > 0))
                Player.Play();
        }
        // stop button pressed
        private void picStop_Click(object sender, EventArgs e)
        {
            Library.FileSelector.FlashControl((Control)sender);
            Player.Stop();
        }

		public delegate bool PlayerAction();

        // next button pressed
        private void picNext_Click(object sender, EventArgs e)
        {
            Library.FileSelector.FlashControl((Control)sender);
            circumventTransitioningHang(new PlayerAction(Player.Next));
        }
        // prev button pressed
        private void picPrev_Click(object sender, EventArgs e)
        {
            Library.FileSelector.FlashControl((Control)sender);
            circumventTransitioningHang(new PlayerAction(Player.Previous));
        }
        // sometimes the player gets stuck in transitioning state
        // the only thing that gets it going again is play()
        // this doesn't happen if player is already in play state (only paused/stopped)
        void circumventTransitioningHang(PlayerAction action)
        {
            //bool needStop = false;
            //try
            //{
            //    if (Player.Status != ePlayerStatus.PLAYING)
            //    {
            //        needStop = true;
            //        Player.Play();
            //        Player.WaitForPlayerStatus(ePlayerStatus.PLAYING);
            //    }
                action();
            //    if (needStop)
            //    {
            //        Player.WaitForPlayerStatus(ePlayerStatus.PLAYING);
            //        Player.Stop();
            //    }
            //}
            //catch { }
        }
        // sleep presed
        private void picSleep_Click(object sender, EventArgs e)
        {
            // convert sleeptime to minutes from now
            foreach (int minutesInterval in SleepIntervals)
            {
                // allow 5 secs to jump between intervals
                if ((SleepTime.AddSeconds(5).Subtract(DateTime.Now)).TotalMinutes < 
                    minutesInterval)
                {
                    SleepTime = DateTime.Now.AddMinutes(minutesInterval);
                    SleepActive = true;
                    lblSleep.Visible = true;
                    DrawSleepTime();
                    return;
                }
            }
            SleepTime = DateTime.Now;
            SleepActive = false;
            lblSleep.Visible = false;
            DrawSleepTime();
        }
        // display sleep time
        void DrawSleepTime()
        {
            if (SleepActive)
                lblSleep.Text = "Sleep in: " +
                    (SleepTime.Subtract(DateTime.Now)).ToString();
            else 
                lblSleep.Text = "";
        }
        // try to pause before popup
        private void cnm_Popup(object sender, EventArgs e)
        {
            if (Player.Status == ePlayerStatus.PLAYING)
            {
                Player.Pause();
                Player.WaitForPlayerStatus(ePlayerStatus.PAUSED);
            }
        }
        // paint screen
        private void abPlayer_Paint(object sender, PaintEventArgs e)
        {
            PaintScreen(e.Graphics);
        }
        // properties button clicked
        private void picProps_Click(object sender, EventArgs e)
        {
            Library.FileSelector.FlashControl((Control)sender);
            // only if we have a playlist
            if (Player.PlaylistCount <= 0) return;
            // if we are in a play state - try to pause
            if (Player.Status == ePlayerStatus.PLAYING)
            {
                Player.Pause();
                Player.WaitForPlayerStatus(ePlayerStatus.PAUSED);
            }
            // if we failed (or state is something else - deny access)
            if ((Player.Status != ePlayerStatus.PAUSED) &&
                (Player.Status != ePlayerStatus.STOPPED)) return;
            // set all property values to their current state
            // make properties form accessible
            DeviceSpecifics.BacklightTimeout = 0;
            if (Props.ShowDialog() == DialogResult.OK)
            {
                if ((Props.Dirty) && (Player.Status == ePlayerStatus.PAUSED))
                {
                    if (Props.hscVol.Value != Library.BookStore.GetBookProperty(eBookProperty.VOLUME, ""))
                    {
                        Library.BookStore.SetBookProperty(eBookProperty.VOLUME, Props.hscVol.Value, "");
                        DeviceSpecifics.Volume = Props.hscVol.Value;
                    }
                    // shuffle option changed
                    if (Props.chkShuffle.Checked != (Library.BookStore.GetBookProperty(eBookProperty.SHUFFLE, "") != 0))
                    {
                        Library.BookStore.SetBookProperty(eBookProperty.SHUFFLE, (Props.chkShuffle.Checked ? 1 : 0), "");
                        Player.Shuffle = Props.chkShuffle.Checked;
                    }
                    // playlist entry  
                    if ((Props.hscEntry.Value - 1) != Library.BookStore.GetBookProperty(eBookProperty.BOOKMARK_ENTRY, ""))
                    {
                        Library.BookStore.SetBookProperty(eBookProperty.BOOKMARK_ENTRY, Props.hscEntry.Value - 1, "");
                        Library.BookStore.SetBookProperty(eBookProperty.BOOKMARK_LOCATION, Props.hscTime.Value, "");
                        Player.Playlist(null,
                                Props.hscEntry.Value - 1,
                                Props.hscTime.Value,
                                Props.chkShuffle.Checked);
                        PaintScreen();
                    }
                    else
                    // timeline marker changed 
                    if (Props.hscTime.Value != Library.BookStore.GetBookProperty(eBookProperty.BOOKMARK_LOCATION, ""))
                    {
                        Library.BookStore.SetBookProperty(eBookProperty.BOOKMARK_LOCATION, Props.hscTime.Value, "");
                        Player.Location = Props.hscTime.Value;
                    }
                    //indicate change done & we are ready to play
                    DeviceSpecifics.Beep();
                }
            }
            if(picDark.Visible)
                DeviceSpecifics.BacklightTimeout = BACKLIGHT_TIMEOUT;
        }
        // library button clicked
        private void picLibrary_Click(object sender, EventArgs e)
        {
            Library.FileSelector.FlashControl((Control)sender);
            // if we are in a playing state - try to pause
            if (Player.Status == ePlayerStatus.PLAYING)
            {
                Player.Pause();
                if (!Player.WaitForPlayerStatus(ePlayerStatus.PAUSED))
                    return;
            }
            // show library form and:
            DeviceSpecifics.BacklightTimeout = 0;
            if ((Library.ShowDialog() == DialogResult.OK) ||
                ((Player.PlaylistCount > 0) &&
                (Player.PlaylistCount != Library.BookStore.GetBookFileCount(""))))
            {
                // we came back after user pressed play
                tmr.Enabled = false;
                PaintScreen();
                Application.DoEvents();
                // reset current playlist
                Player.StopAndClear();
                // set volume
                Props.hscVol.Value = Library.BookStore.GetBookProperty(eBookProperty.VOLUME, "");
                Props.lblVol.Text = "Volume: " + Props.hscVol.Value.ToString();
                DeviceSpecifics.Volume = Props.hscVol.Value;
                // load playlist and start playing it from the last position
                Player.Playlist(Library.BookStore.GetBookFiles(""),
                                Library.BookStore.GetBookProperty(eBookProperty.BOOKMARK_ENTRY, ""),
                                Library.BookStore.GetBookProperty(eBookProperty.BOOKMARK_LOCATION, ""),
                                (Library.BookStore.GetBookProperty(eBookProperty.SHUFFLE, "") != 0));
                GC.Collect();
                DeviceSpecifics.Beep();
                tmr.Enabled = true;
                PaintScreen();
            }
            else
            {
                // we came back after user pressed the cancel button
                // if active book was deleted - reset player
                if (Library.BookStore.ActiveBookName == "")
                    Player.StopAndClear();
                PaintScreen();
            }
            if (picDark.Visible)
                DeviceSpecifics.BacklightTimeout = BACKLIGHT_TIMEOUT;
        }
        // get battery life percent and according to its level set the
        // display color: charging=white, good=yellow, medium=orange, low=red
        private int GetBatteryLifePercentAndSetTextColor()
        {
            PowerState state = DeviceSpecifics.PowerAndBatteryState;
            Color c;
            if (state.ACLineConnected)
                c = Color.White;
            else
                c = (state.BatteryLifePercent <= 35) ? Color.Red :
                    (state.BatteryLifePercent <= 70) ? Color.Orange : Color.Yellow;
            if (c != TextColor)
            {
                TextColor = c;
                PaintScreen();
            }
            return state.BatteryLifePercent;
        }
        // key press function
        private void frmPlayer_KeyDown(object sender, KeyEventArgs e)
        {
            //if (Player.PlaylistCount <= 0) return;
            switch (e.KeyCode)
            {
                case Keys.Right:
                    AdjustLocation(TIME_CHANGE);
                    break;
                case Keys.Left:
                    AdjustLocation(-TIME_CHANGE);
                    break;
                case Keys.Up:
                    AdjustVolume(-VOLUME_CHANGE);
                    break;
                case Keys.Down:
                    AdjustVolume(VOLUME_CHANGE);
                    break;
                case Keys.Enter:
                    SwitchState();
                    break;
            }
            e.Handled = true;
        }
        // volume manipulation function
        private void AdjustVolume(int delta)
        {
            int vol = DeviceSpecifics.Volume;
            int newVol = ((vol + delta) < 0) ? 0 :
                ((vol + delta) > 100) ? 100 :
                (vol + delta);
            if (vol != newVol)
            {
                DeviceSpecifics.Volume = newVol;
                Library.BookStore.SetBookProperty(eBookProperty.VOLUME, newVol, "");
                PaintBatteryVolAndTOD();
            }
        }
        // location manipulation function
        private void AdjustLocation(int delta)
        {
            int loc = Player.Location;
            int dur = Player.Duration;
            if ((loc != -1) &&
                (dur != -1))
            {
                int newLoc = ((loc + delta) < 0) ? 0 :
                    ((loc + delta) > dur) ? dur :
                    (loc + delta);
                if (newLoc != loc)
                {
                    Player.Location = newLoc; 
                    Library.BookStore.SetBookProperty(eBookProperty.BOOKMARK_LOCATION,
                        newLoc, "");
                    PaintLocation();
                }
            }
        }
        // switch between play and pause
        private void SwitchState()
        {
            if (Player.PlaylistCount > 0)
            {
                if (Player.Status == ePlayerStatus.PLAYING)
                    Player.Pause();
                else
                    Player.Play();
            }
        }
        // show about dialog
        private void mnuAbout_Click(object sender, EventArgs e)
        {
            DeviceSpecifics.BacklightTimeout = 0;
            frmAbout frm = new frmAbout();
            frm.Left = Width / 2 - frm.Width / 2;
            frm.Top = Height / 2 - frm.Height / 2;
            frm.ShowDialog();
            if (picDark.Visible)
                DeviceSpecifics.BacklightTimeout = BACKLIGHT_TIMEOUT;
            PaintScreen();
        }
    }
}