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Disabling smooth scrolling

I have a Panel in which a VerticalScroll is used. When the user clicks the VerticalScroll and drags it, the VerticalScroll scrolls smoothly. This is what I do not want to have. Rather than scrolling smoothly, I would like the VerticalScroll to scroll in discrete steps, to be precise in the same steps as I specified in the property SmallChange. How can I do that?
Edit: It basically seems to work when overriding the OnPaint method of the Panel, but how can I suppress the call to base.OnPaint conditionally?
This code sets the position of the Vertical Scroll to the right value:
protected override void OnPaint(PaintEventArgs e)
{
int v = this.VerticalScroll.Value;
this.VerticalScroll.Value = Math.Max(0, Form1.AlignFileButtonHeight(v, v + 1));
}
But it has the effect that the window "blinks" for an instant! How can I avoid that?
Edit: The best result I have achieved so far, I have achieved by overriding the OnScroll method:
protected override void OnScroll(ScrollEventArgs se)
{
if (se.Type == ScrollEventType.ThumbTrack)
{
int v = se.NewValue;
v = Math.Max(0, Form1.AlignFileButtonHeight(v, v + 1));
this.VerticalScroll.Value = v;
this.Refresh();
se.NewValue = v;
base.OnScroll(se);
this.Refresh();
base.OnScroll(se);
}
}
It still blinks a bit, but not as much as when overriding the OnPaint method. However, I'd like to get rid of blinking entirely.
Edit: I also tried this, with only very limited success.
protected override void OnScroll(ScrollEventArgs se)
{
if (se.Type == ScrollEventType.ThumbTrack && se.NewValue != se.OldValue)
{
int diff = se.NewValue - se.OldValue;
foreach (Control c in this.Controls)
{
int x = c.Location.X;
int y = c.Location.Y;
y = y + diff;
c.Location = new Point(x, y);
}
if (se.NewValue % Form1.fileButtonHeight == 0)
{
foreach (Control c in this.Controls)
{
int x = c.Location.X;
int y = c.Location.Y;
y = y + (diff < 0 ? 1 : -1) * Form1.fileButtonHeight;
c.Location = new Point(x, y);
}
}
}
}

Getting DataPoint with mouse X coordinate only

I need to access the DataPoint via X coordinate, but I can't seem to find any solutions for it. HitTest() is out, since it also needs Y coordinate (cannot hit anything if Y is 0). I know I could select the DataPoints via Linq and the X coordinate, but I was wondering if there are better solutions for this?
More specifically I'm trying to show Candlestick data (Open, Low, High, Close and DateTime) with a TextAnnotation, which follows the CursorX (it's anchored above my X-axis, which is located at the bottom of my chart), and my CursorX is intervalled so it is always in the center of a candle.
What I have so far, is a MouseMove function, which updates my CursorX, but lacks the data access and label update:
PointF _mouse = new PointF();
TextAnnotation _mouseLabel;
void UpdateMouseCursor(object sender, MouseEventArgs e)
{
if( _mouseLabel == null )
return;
_mouse.X = e.Location.X;
_mouse.Y = e.Location.Y;
var cursorX = chart1.ChartAreas[0].CursorX;
cursorX.SetCursorPixelPosition( _mouse, true );
_mouseLabel.X = cursorX.Position;
}
CursorX and _mouseLabel setup:
public void SetupMouse(double interval, DateTimeIntervalType intervalType)
{
chart1.ChartAreas[0].CursorX.IntervalType = intervalType;
chart1.ChartAreas[0].CursorX.Interval = interval;
chart1.ChartAreas[0].CursorX.LineColor = Color.FromArgb(128, 128,128,128);
if( _mouseLabel == null )
{
_mouseLabel = new TextAnnotation();
_mouseLabel.Text = "WOOHOO!";
_mouseLabel.AnchorY = 85;
_mouseLabel.AxisX = chart1.ChartAreas[0].AxisX;
chart1.Annotations.Add( _mouseLabel );
}
}
The visuals:

Prevent ToolStripMenuItems from jumping to second screen

I have an application that is mostly operated through NotifyIcon's ContextMenuStrip
There are multiple levels of ToolStripMenuItems and the user can go through them.
The problem is, that when the user has two screen, the MenuItems jump to second screen when no space is available. like so:
How can I force them to stay on the same screen? I've tried to search through the web but couldn't find an appropriate answer.
Here is a sample piece of code i'm using to test this senario:
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
var resources = new ComponentResourceManager(typeof(Form1));
var notifyIcon1 = new NotifyIcon(components);
var contextMenuStrip1 = new ContextMenuStrip(components);
var level1ToolStripMenuItem = new ToolStripMenuItem("level 1 drop down");
var level2ToolStripMenuItem = new ToolStripMenuItem("level 2 drop down");
var level3ToolStripMenuItem = new ToolStripMenuItem("level 3 drop down");
notifyIcon1.ContextMenuStrip = contextMenuStrip1;
notifyIcon1.Icon = ((Icon)(resources.GetObject("notifyIcon1.Icon")));
notifyIcon1.Visible = true;
level2ToolStripMenuItem.DropDownItems.Add(level3ToolStripMenuItem);
level1ToolStripMenuItem.DropDownItems.Add(level2ToolStripMenuItem);
contextMenuStrip1.Items.Add(level1ToolStripMenuItem);
}
}

It is not easy, but you can write code in the DropDownOpening event to look at where the menu is at (its bounds), the current screen, and then set the DropDownDirection of the ToolStripMenuItem:
private void submenu_DropDownOpening(object sender, EventArgs e)
{
ToolStripMenuItem menuItem = sender as ToolStripMenuItem;
if (menuItem.HasDropDownItems == false)
{
return; // not a drop down item
}
// Current bounds of the current monitor
Rectangle Bounds = menuItem.GetCurrentParent().Bounds;
Screen CurrentScreen = Screen.FromPoint(Bounds.Location);
// Look how big our children are:
int MaxWidth = 0;
foreach (ToolStripMenuItem subitem in menuItem.DropDownItems)
{
MaxWidth = Math.Max(subitem.Width, MaxWidth);
}
MaxWidth += 10; // Add a little wiggle room
int FarRight = Bounds.Right + MaxWidth;
int CurrentMonitorRight = CurrentScreen.Bounds.Right;
if (FarRight > CurrentMonitorRight)
{
menuItem.DropDownDirection = ToolStripDropDownDirection.Left;
}
else
{
menuItem.DropDownDirection = ToolStripDropDownDirection.Right;
}
}
Also, make sure you have the DropDownOpening event hooked up (you would really need to add this to every menu item):
level1ToolStripMenuItem += submenu_DropDownOpening;

I have solved it this way:
For the ContextMenuStrip itself to open on a desired screen, I created a ContextMenuStripEx with the following methods:
protected override void SetBoundsCore(int x, int y, int width, int height, BoundsSpecified specified)
{
Rectangle dropDownBounds = new Rectangle(x, y, width, height);
dropDownBounds = ConstrainToBounds(Screen.FromPoint(dropDownBounds.Location).Bounds, dropDownBounds);
base.SetBoundsCore(dropDownBounds.X, dropDownBounds.Y, dropDownBounds.Width, dropDownBounds.Height, specified);
}
internal static Rectangle ConstrainToBounds(Rectangle constrainingBounds, Rectangle bounds)
{
if (!constrainingBounds.Contains(bounds))
{
bounds.Size = new Size(Math.Min(constrainingBounds.Width - 2, bounds.Width), Math.Min(constrainingBounds.Height - 2, bounds.Height));
if (bounds.Right > constrainingBounds.Right)
{
bounds.X = constrainingBounds.Right - bounds.Width;
}
else if (bounds.Left < constrainingBounds.Left)
{
bounds.X = constrainingBounds.Left;
}
if (bounds.Bottom > constrainingBounds.Bottom)
{
bounds.Y = constrainingBounds.Bottom - 1 - bounds.Height;
}
else if (bounds.Top < constrainingBounds.Top)
{
bounds.Y = constrainingBounds.Top;
}
}
return bounds;
}
(ConstrainToBounds method is taken from the base class ToolStripDropDown via Reflector)
for the nested MenuItems to open on the same screen as ContextMenuStrip, I created a ToolStripMenuItemEx (which derives from ToolStripMenuItem). In my case it looks like this:
private ToolStripDropDownDirection? originalToolStripDropDownDirection;
protected override void OnDropDownShow(EventArgs e)
{
base.OnDropDownShow(e);
if (!Screen.FromControl(this.Owner).Equals(Screen.FromPoint(this.DropDownLocation)))
{
if (!originalToolStripDropDownDirection.HasValue)
originalToolStripDropDownDirection = this.DropDownDirection;
this.DropDownDirection = originalToolStripDropDownDirection.Value == ToolStripDropDownDirection.Left ? ToolStripDropDownDirection.Right : ToolStripDropDownDirection.Left;
}
}

The code of #David does not fix if the menu is opened in the left side of second screen. I have improved that code to work on all screen corner.
private void subMenu_DropDownOpening(object sender, EventArgs e)
{
ToolStripMenuItem mnuItem = sender as ToolStripMenuItem;
if (mnuItem.HasDropDownItems == false)
{
return; // not a drop down item
}
//get position of current menu item
var pos = new Point(mnuItem.GetCurrentParent().Left, mnuItem.GetCurrentParent().Top);
// Current bounds of the current monitor
Rectangle bounds = Screen.GetWorkingArea(pos);
Screen currentScreen = Screen.FromPoint(pos);
// Find the width of sub-menu
int maxWidth = 0;
foreach (var subItem in mnuItem.DropDownItems)
{
if (subItem.GetType() == typeof(ToolStripMenuItem))
{
var mnu = (ToolStripMenuItem) subItem;
maxWidth = Math.Max(mnu.Width, maxWidth);
}
}
maxWidth += 10; // Add a little wiggle room
int farRight = pos.X + mnuMain.Width + maxWidth;
int farLeft = pos.X - maxWidth;
//get left and right distance to compare
int leftGap = farLeft - currentScreen.Bounds.Left;
int rightGap = currentScreen.Bounds.Right - farRight;
if (leftGap >= rightGap)
{
mnuItem.DropDownDirection = ToolStripDropDownDirection.Left;
}
else
{
mnuItem.DropDownDirection = ToolStripDropDownDirection.Right;
}
}

I did not try the solution by tombam. But since the others didn't seem to work, I came up with this simple solution:
private void MenuDropDownOpening(object sender, EventArgs e)
{
var menuItem = sender as ToolStripDropDownButton;
if (menuItem == null || menuItem.HasDropDownItems == false)
return; // not a drop down item
// Current bounds of the current monitor
var upperRightCornerOfMenuInScreenCoordinates = menuItem.GetCurrentParent().PointToScreen(new Point(menuItem.Bounds.Right, menuItem.Bounds.Top));
var currentScreen = Screen.FromPoint(upperRightCornerOfMenuInScreenCoordinates);
// Get width of widest child item (skip separators!)
var maxWidth = menuItem.DropDownItems.OfType<ToolStripMenuItem>().Select(m => m.Width).Max();
var farRight = upperRightCornerOfMenuInScreenCoordinates.X + maxWidth;
var currentMonitorRight = currentScreen.Bounds.Right;
menuItem.DropDownDirection = farRight > currentMonitorRight ? ToolStripDropDownDirection.Left :
ToolStripDropDownDirection.Right;
}
Note that in my world, I was not concerned about multiple levels of cascading menus (as in the OP), so I did not test my solution in that scenario. But this works correctly for a single ToolStripDropDownButton on a ToolStrip.

How can I instantiate large number of buttons in Windows Forms?

I'm developing a theatre reservation software. I'm using Windows Forms, the seats is represented by a 2-dimensioned array. And I draw the buttons as following:
public void DrawSeats()
{
// pnl_seats is a Panel
pnl_seats.Controls.Clear();
// Here I store all Buttons instance, to later add all buttons in one call (AddRange) to the Panel
var btns = new List<Control>();
// Suspend layout to avoid undesired Redraw/Refresh
this.SuspendLayout();
for (int y = 0; y < _seatZone.VerticalSize; y++)
{
for (int x = 0; x < _seatZone.HorizontalSize; x++)
{
// Check if this seat exists
if (IsException(x, y))
continue;
// Construct the button with desired properties. SeatSize is a common value for every button
var btn = new Button
{
Width = SeatSize,
Height = SeatSize,
Left = (x * SeatSize),
Top = (y * SeatSize),
Text = y + "" + x,
Tag = y + ";" + x, // When the button clicks, the purpose of this is to remember which seat this button is.
Font = new Font(new FontFamily("Microsoft Sans Serif"), 6.5f)
};
// Check if it is already reserved
if (ExistsReservation(x, y))
btn.Enabled = false;
else
btn.Click += btn_seat_Click; // Add click event
btns.Add(btn);
}
}
// As said before, add all buttons in one call
pnl_seats.Controls.AddRange(btns.ToArray());
// Resume the layout
this.ResumeLayout();
}
But already with a seat zone of 20 by 20 (400 buttons), it spent almost 1 minute to draw it, and in debug I checked that the lack of performance, is the instantiation of the buttons.
There is a way to make it faster? Perhaps disable all events during the instatiation or another lightweight Control that has the Click event too?
UPDATE:
lbl was a test, the correct is btn, sorry.
UPDATE 2:
Here is the IsException and ExistsReservations methods:
private bool IsException(int x, int y)
{
for (var k = 0; k < _seatsExceptions.GetLength(0); k++)
if (_seatsExceptions[k, 0] == x && _seatsExceptions[k, 1] == y)
return true;
return false;
}
private bool ExistsReservation(int x, int y)
{
for (var k = 0; k < _seatsReservations.GetLength(0); k++)
if (_seatsReservations[k, 0] == x && _seatsReservations[k, 1] == y)
return true;
return false;
}

Suppose that you change your arrays for reservations and exclusions to
public List<string> _seatsExceptions = new List<string>();
public List<string> _seatsReservations = new List<string>();
you add your exclusions and reservations in the list with something like
_seatsExceptions.Add("1;10");
_seatsExceptions.Add("4;19");
_seatsReservations.Add("2;5");
_seatsReservations.Add("5;5");
your checks for exclusions and reservations could be changed to
bool IsException(int x, int y)
{
string key = x.ToString() + ";" + y.ToString();
return _seatsExceptions.Contains(key);
}
bool ExistsReservation(int x, int y)
{
string key = x.ToString() + ";" + y.ToString();
return _seatsReservations.Contains(key);
}
of course I don't know if you are able to make this change or not in your program. However consider to change the search on your array sooner or later.
EDIT I have made some tests, and while a virtual grid of 20x20 buttons works acceptably well (31 millisecs 0.775ms on average), a bigger one slows down noticeably. At 200x50 the timing jumps to 10 seconds (1,0675 on average). So perhaps a different approach is needed. A bound DataGridView could be a simpler solution and will be relatively easy to handle.

I also won't use such a myriad of controls to implement such a thing. Instead you should maybe create your own UserControl, which will paint all the seats as images and reacts on a click event.
To make it a little easier for you i created such a simple UserControl, that will draw all the seats and reacts on a mouse click for changing of the state. Here it is:
public enum SeatState
{
Empty,
Selected,
Full
}
public partial class Seats : UserControl
{
private int _Columns;
private int _Rows;
private List<List<SeatState>> _SeatStates;
public Seats()
{
InitializeComponent();
this.DoubleBuffered = true;
_SeatStates = new List<List<SeatState>>();
_Rows = 40;
_Columns = 40;
ReDimSeatStates();
MouseUp += OnMouseUp;
Paint += OnPaint;
Resize += OnResize;
}
public int Columns
{
get { return _Columns; }
set
{
_Columns = Math.Min(1, value);
ReDimSeatStates();
}
}
public int Rows
{
get { return _Rows; }
set
{
_Rows = Math.Min(1, value);
ReDimSeatStates();
}
}
private Image GetPictureForSeat(int row, int column)
{
var seatState = _SeatStates[row][column];
switch (seatState)
{
case SeatState.Empty:
return Properties.Resources.emptySeat;
case SeatState.Selected:
return Properties.Resources.choosenSeat;
default:
case SeatState.Full:
return Properties.Resources.fullSeat;
}
}
private void OnMouseUp(object sender, MouseEventArgs e)
{
var heightPerSeat = Height / (float)Rows;
var widthPerSeat = Width / (float)Columns;
var row = (int)(e.X / widthPerSeat);
var column = (int)(e.Y / heightPerSeat);
var seatState = _SeatStates[row][column];
switch (seatState)
{
case SeatState.Empty:
_SeatStates[row][column] = SeatState.Selected;
break;
case SeatState.Selected:
_SeatStates[row][column] = SeatState.Empty;
break;
}
Invalidate();
}
private void OnPaint(object sender, PaintEventArgs e)
{
var heightPerSeat = Height / (float)Rows;
var widthPerSeat = Width / (float)Columns;
e.Graphics.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
e.Graphics.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
e.Graphics.PixelOffsetMode = System.Drawing.Drawing2D.PixelOffsetMode.HighQuality;
e.Graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
for (int row = 0; row < Rows; row++)
{
for (int column = 0; column < Columns; column++)
{
var seatImage = GetPictureForSeat(row, column);
e.Graphics.DrawImage(seatImage, row * widthPerSeat, column * heightPerSeat, widthPerSeat, heightPerSeat);
}
}
}
private void OnResize(object sender, System.EventArgs e)
{
Invalidate();
}
private void ReDimSeatStates()
{
while (_SeatStates.Count < Rows)
_SeatStates.Add(new List<SeatState>());
if (_SeatStates.First().Count < Columns)
foreach (var columnList in _SeatStates)
while (columnList.Count < Columns)
columnList.Add(SeatState.Empty);
while (_SeatStates.Count > Rows)
_SeatStates.RemoveAt(_SeatStates.Count - 1);
if (_SeatStates.First().Count > Columns)
foreach (var columnList in _SeatStates)
while (columnList.Count > Columns)
columnList.RemoveAt(columnList.Count - 1);
}
}
This will currently draw forty rows and columns (so there are 800 seats) and you can click on each seat to change its state.
Here are the images i used:
EmtpySeat:
ChoosenSeat:
FullSeat:
If you anchor this control and resize it or you click on a seat to change its state there can be some minor lacking for the repainting if you further increase the number of rows or columns, but that is still somewhere far below one second. If this still hurts you, you have to improve the paint method and maybe check the ClipRectangle property of the paint event and only paint the really needed parts, but that's another story.

Rather than using actual button controls, just draw the image of the seats then when the user clicks on a seat translate the mouse X,Y coordinates to determine which seat was clicked. This will be more efficient. Of course, the drawback is that you have to write the method to translate x,y coordinates to a seat, but that really isn't that difficult.

EDIT; it has been pointed out to me this will not work in Windows Forms!
Well, you are Sequentially working through it.
if one iteration costs 1 sec, the full process will take 400*1 in time.
Perhaps you should try and make a collection of your objects, and process it 'parallel'.
try the .Net framework (4 and above) 'parallel foreach' method:
http://msdn.microsoft.com/en-s/library/system.threading.tasks.parallel.foreach(v=vs.110).aspx
edit: so, if you have a list buttonnames, you can say
buttonNames.ForEach(x=>CreateButton(x));
while your CreateButton() method is as following:
private Button CreateButton(string nameOfButton) { Button b = new
Button(); b.Text = nameOfButton; //do whatever you want...
return b; }

checking a color of a button and changing it using a 2D array

I'm creating a small game just like the game Reversi/Othello I have managed to created a 2x3 board with buttons.
The buttons change colour ones you click on them but I'm having trouble to detect if there is a white colour in between 2 black colours and if so change that white colour into black.. I hope this make sense. the buttons are in a 2D array. Any suggestions that could help me do this would be much appreciated.
The image:
Here is my code:
![namespace reversitest
{
public partial class Form1 : Form
{
private Button\[,\] squares;
public Form1()
{
InitializeComponent();
squares = new Button\[3, 2\];
squares = new Button\[,\] {{button1, button2, button3},
{button4, button5, button6,}};
}
private void Form1_Load(object sender, EventArgs e)
{
foreach (Button sqrr in squares)
{
sqrr.Click += new System.EventHandler(this.DrawCharacter);
}
}
int _turn = 0;
private void DrawCharacter(object sender, EventArgs e)
{
Button sqrr = (Button)sender;
int col = 0;
if (sqrr.BackColor.Equals(Color.Black) || sqrr.BackColor.Equals(Color.White))
{
MessageBox.Show("Move Not Allowed!");
}
else
{
for ( int i = 0; i < squares.GetLongLength(1); ++i)
{
// check othere squares and change color
if (i < 2)
{
for (int f = 0; f < 3; ++f)
{
var ss = squares\[i, f\];
if (ss.BackColor.Equals(Color.Black))
{
MessageBox.Show("we have a black");
//ss = squares\[i, f+1\];
ss.BackColor = Color.Black;
}
else
{
MessageBox.Show("no black");
}
}
}
if (_turn == 0)
{
_turn = 1;
sqrr.BackColor = Color.Black;
}
else
{
_turn = 0;
sqrr.BackColor = Color.White;
}
}
}
}
}
}

First name your buttons with the array index. It will help you to find the button.
For example according to you picture button1 name would be btn_1_1.
Then inside your button click event first get the button name and then identify the button positioned.
Button b = sender as Button;
string[] btnData = b.Name.Split('_');
int x = int.Parse(btnData[1]);
int y = int.Parse(btnData[2]);
//check for possible combinations
int top = y - 2;
int botton = y + 2;
int left = x - 2;
int right = x + 2;
if (top >= 0 && squares[top, y].Background == Color.Black)
{
squares[top+1, y].Background = Color.Black;
}
...
...
Continue like that. If you need more detail please free to ask.

Final Answer
//check for possible combinations
int top = x - 2;
int botton = x + 2;
int left = y - 2;
int right = y + 2;
if (top >= 0 && squares[top, y].BackColor == Color.Black)
{
squares[top + 1, y].BackColor = Color.Black;
}
else if (left >= 0 && squares[x, left].BackColor == Color.Black)
{
squares[x, left + 1].BackColor = Color.Black;
}
else if (left >= 0 && squares[x, left].BackColor == Color.Black)
{
squares[x, left + 1].BackColor = Color.Black;
}
Will be extended for a 8x8 board later on

Do you need it to be elegant? A kind of brute force method: You could check for pieces in the 8 different directions it is possible for them to be aligned. So for example, you start with a black piece. Check the next piece over in one direction. If it's white, keep going and take a note of the position that was white so you can change it to black later. When you finally hit a black piece, change all the stored positions to black and move on to the next direction and repeat the process until you've done all 8 directions.