Title: Add an icon to task bar and recieve mouse messages from the icon
Question: How to Add an icon to task bar and recieve mouse messages from the icon
Answer:
I have updated the component adding some more events and also fixed some bugs. I also added variables x and y to all events so it is easier to show a popup menu at the icon when it is clicked.
You can add an icon to the taskbar by calling the function SHellNotifyIcon;
the first parameter can take the following values
NIM_ADD:adds an icon to taskbar
NIM_MODIFY: modifies the icon on taskbar
NIM_DELETE: removes the icon from taskbar;
the second parameter is a pointer to the NOTIFYICONDATA structure
NOTIFYICONDATA
cbSize: size of structure;
hWnd: handle of window to recieve messages;
uID:id of icon
uFlags:
can take following values
Members
NIF_ICON :specifies if The hIcon member is valid.
NIF_MESSAGE :specifies if The uCallbackMessage member is valid.
NIF_TIP :specifies if The szTip member is valid.
uCallbackMessage: Application-defined message identifier.
The system uses the specified identifier for notification messages that it sends to the window identified by hWnd whenever a mouse event occurs in the bounding rectangle of the icon.
hIcon: Handle of the icon to add, modify, or delete.
szTip:Tooltip text to display for the icon.
I have created a component that adds an icon to the task bar.
Here is the code
unit StatusIcon;
interface
uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,shellapi;
type
TMouseEvent = procedure(x:integer;y:integer;sender:tobject) of object;
type
TStatusIcon = class(TWinControl)
protected
ficondata:TNotifyIconData;
ficon:ticon;
fid:integer;
fhint:string;
fadded:boolean;
flclick:TMouseEvent;
frclick:TMouseEvent;
fldblclick:TMouseEvent;
frdblclick:TMouseEvent;
fmove:TMouseEvent;
procedure seticon(aicon:ticon);
procedure setid(aid:integer);
procedure sethint(ahint:string);
procedure SINotifyIcon(var msg:Tmessage);message WM_USER+1;
procedure loaded;override;
procedure WMPAINT(var msg:Tmessage);message WM_PAINT;
public
constructor create(Aowner:tcomponent);override;
destructor destroy; override;
function AddToTaskbar:boolean;
function RemoveFromTaskbar:boolean;
function Modify:boolean;
property added:boolean read fadded;
procedure setbounds(left:integer;top:integer;width:integer;height:integer);override;
published
property Icon:Ticon read ficon write seticon;
property ID:integer read fid write setid;
property OnLeftClick:TMouseEvent read flclick write flclick;
property OnRightClick:TMousEEvent read frclick write frclick;
property OnMouseMove:TMouseEvent read fmove write fmove;
property OnLeftDoubleClick:TMouseEvent read fldblclick write fldblclick;
property OnRightDoubleClick:TMouseEvent read frdblclick write frdblclick;
property Hint read fhint write sethint;
end;
const
sibase= WM_user+1;
procedure Register;
implementation
procedure tstatusicon.sethint(ahint:string);
var
i:integer;
begin
inherited;
fhint:=ahint;
for i:=1 to length(hint) do
ficondata.szTip[i-1]:=fhint[i];
end;
procedure tstatusicon.setid(aid:integer);
begin
fid:=aid;
ficondata.uID:=fid;
end;
procedure tstatusicon.setbounds(left:integer;top:integer;width:integer;height:integer);
begin
width:=28;
height:=28;
inherited;
end;
procedure tstatusicon.WMPAINT(var msg:Tmessage);
var
rec:trect;
dc:hdc;
begin
if csdesigning in componentstate then
begin
dc:=getdc(handle);
rec:=clientrect;
drawedge(dc,rec,BDR_RAISEDINNER,BF_RECT);
if assigned(ficon) then
drawiconex(dc,rec.left+3,rec.top+3,ficon.Handle,20,20,0,0,DI_NORMAL or DI_DEFAULTSIZE);
releasedc(handle,dc);
end;
inherited;
end;
function tstatusicon.modify:boolean;
begin
result:=false;
if fadded=true then
result:=Shell_NotifyIcon(NIM_MODIFY,@ficondata);
end;
procedure tstatusicon.loaded;
begin
inherited;
ficondata.cbSize:=sizeof(ficondata);
ficondata.Wnd:=handle;
ficondata.hIcon:=ficon.Handle;
ficondata.uID:=fid;
ficondata.uFlags:=NIF_MESSAGE;
ficondata.uCallbackMessage:=sibase;
if length(trim(hint))0 then
ficondata.uFlags:=ficondata.uFlags or NIF_TIP;
if assigned(ficon) then
ficondata.uFlags:=ficondata.uFlags or NIF_ICON;
if not(csdesigning in componentstate) then
visible:=false;
end;
function Tstatusicon.RemoveFromTaskbar:boolean;
var
tmp:boolean;
begin
tmp:=Shell_NotifyIcon(NIM_DELETE,@ficondata);
if tmp=true then
fadded:=false;
result:=tmp;
end;
procedure Tstatusicon.SINotifyIcon(var msg:Tmessage);
begin
inherited;
if (msg.wparam=fid) then
begin
if (msg.LParam=WM_LBUTTONDOWN) then
if assigned(flclick) then
flclick(mouse.CursorPos.x,mouse.Cursorpos.y,self);
if (msg.lparam=WM_RBUTTONDOWN) then
if assigned(frclick) then
frclick(mouse.CursorPos.x,mouse.Cursorpos.y,self);
if (msg.lparam=WM_MOUSEMOVE) then
if assigned(fmove) then
fmove(mouse.CursorPos.x,mouse.Cursorpos.y,self);
if (msg.lparam=WM_LBUTTONDBLCLK) then
if assigned(fldblclick) then
fldblclick(mouse.CursorPos.x,mouse.Cursorpos.y,self);
if (msg.lparam=WM_RBUTTONDBLCLK) then
if assigned(frdblclick) then
frdblclick(mouse.CursorPos.x,mouse.Cursorpos.y,self);
end;
end;
constructor Tstatusicon.create(Aowner:tcomponent);
begin
inherited;
ficon:=ticon.Create;
fid:=1;
fadded:=false;
end;
destructor tstatusicon.destroy;
begin
inherited;
if fadded = true then
RemoveFromTaskbar;
end;
procedure Tstatusicon.seticon(aicon:ticon);
begin
ficon.Assign(aicon);
ficondata.hIcon:=ficon.handle;
end;
function Tstatusicon.addtotaskbar:boolean;
begin
if fadded=false then
fadded:=Shell_NotifyIcon(NIM_ADD,@ficondata);
result:=fadded;
end;
procedure Register;
begin
RegisterComponents('Samples', [TStatusIcon]);
end;
end.
//copy code to .pas file and then install the component.
call the Addtotaskbar function to put the icon on taskbar.
call the removefromtaskbar function to remove the icon from taskbar.
If after adding the icon you make changes to the hint property, id property or the icon property then call the modify function to see the changes made.
you don't need to call the removefromtaskbar function when you close the application. It will automatically be removed from the taskbar.