I'm new in working with SDL and now I've faced a problem.
Well, I'm about to make a program like Paint.
In order to do that I need a command for mouse that when I'm holding the left button and moving the mouse, a line would be drawing in where the mouse is going.
I have found an event for it, SDL_MouseButtonDown. but it only works for one second like I only click on the screen for one time!
I will appreciate any comments!
The event fires when the button goes down. It doesn't repeatedly fire for as long as the button is down, and this wouldn't be of much use to you anyway.
Write your code so that you set some variable when the button goes down, and unset it when SDL_MouseButtonUp is invoked. Whenever the mouse moves, and your variable is set, draw more of the line.
Related
I have an odd problem here.
I'm working on an application, and within one of my classes I'm monitoring my mouse events.
The weird thing is, my mouse move event will only get called if any mouse button is pressed.
I'm not even filtering for any button presses within the method; the method itself doesn't even get called unless I click on this object itself (the one that's monitoring it).
What generally causes this type of error to happen?
I'm not sure if it's relevant, but I have 2 different things monitoring my mouse inputs: 1) the main program monitoring the global mouse coordinates, and 2) an object within my program monitoring the mouse coordinates within itself.
Edit
So the problem has to be because mouse move event is generally used when people are dragging the cursor along the screen right?
My reason for not needing it like that is because I'm building a custom context menu of sorts, and I need to know when an item is hovered over.
It turns out that I didn't truly set everything within my class to enable mouse tracking.
I somehow thought if the class itself was set to have it enabled, I wouldn't need to set it to all the sub objects, but now I see how that wouldn't make any sense at all.
So just to clarify my solution:
The items that I needed to track my cursor's position needed to have
setMouseTracking(true);
I need to know if there is a code in c++ that allows to simulate a click, on a background window (if that's impossible, a foreground window will do fine), without moving the mouse.
I also need to click on specific coordinates, and drag an item to some other position (always without moving the mouse).
Example:
my mouse pointer is at (500,700),
but i need to left click at (100,150),
and drag to (700,300).
I need to be able to move my mouse pointer without affecting the program,
and the program must run correctly without moving, or locking, the mouse pointer.
If this action is impossible in c++, a VB code will be apreciated.
From a C++ Windows application, you can call Windows API directly by first finding the window using FindWindow that will give you the window handle you want, then finding the area within this window that you want to click. You can use API like GetWindowRect for this.
Finally, you can send this window, or an area within it, mouse messages using mouse_event function to cause the mouse to move, click, drag and let go at a new location.
https://stackoverflow.com/questions/9466359/graphics-editor-in-c
I've developed a simple graphics editor in c++.It requires me to drag the mouse to draw a shape .After drawing the shape I want to fill it by picking a color but since dragging the mouse amounts to a large number of clicks because of which the entire screen gets filled with a default color even before i've drawn the shape. delay() doesn't work either.
the mouse click event in turbo c++ has two part. one where you press the button and two when you release the button. you need to drag so you should use the clrscr() function in the loop which goes on iterating until the mouse button is pressed down along with the code for the shape you want to draw. that way your screen keeps getting updated when you are dragging the mouse. and the loop ends when you release the button.
for filling the shape using the flood fill function should suffice
Perhaps one of the following links is what you're looking for:
http://www.codeproject.com/Articles/11313/Mouse-Programming-in-C-C
http://www.cprogrammingreference.com/Tutorials/Advance_Tutorials/mouseprogramming.php
http://www.brackeen.com/vga/mouse.html
I'm making my first game in Irrlicht (C++), an RTS with mouse control
and when you select a tile (by clicking on it) it lights up and some gui button appear on the screen (not in a gui window mind you, I like it this way):
http://i1139.photobucket.com/albums/n549/Adam_Halley-Prinable/Untitled2.png
However, since i switched to mouse control, the buttons wont register my mouse clicks. The click goes straight through the button and selects the tile behind instead:
http://i1139.photobucket.com/albums/n549/Adam_Halley-Prinable/Untitled3.png
Is there a way I can say "Buttons get top priority for clicks"?
I'm using MyEventReceiver, which i've messed around with to accept mouse clicks and that.
Thanks a bunch :D
If anyone else has the same problem, ill tell you how I solved it :)
Go through the MyEventReceiver.h and get rid of all the "return true;"'s in the mouse section.
Don't ask me why, but it works, and appears to have no side effects. Make sure you leave the "return false;" at the end of the section there.
Your event receiver fires before the GUI gets access to the event, if you want to pass it to the GUI then you can do this by manually posting it to the GUIEnvironment in your event receiver.
if (guienv->postEventFromUser(event))
return true; // abort because the gui wanted it
// .. pick nodes
// possibly post event to scene manager
return true; // remember to return true so gui/smgr don't get the event again
This is my first attempt at writing a QT app, and I'm just trying to get a feel for how it works. My goal is to have a 400x400 widget which knows the exact position of the mouse when the mouse is hovering over it. For example, if the mouse was hovering in the top left corner, the position might be 10,10 (or something similar). If the mouse is in the bottom right corner, it might say 390,390.
Eventually, these coordinates will be displayed in a label on the main window, but that should be trivial. I'm stuck at the actual fetching of the coordinates. Any ideas?
For your widget, you must enable mouse tracking.
Then, you can either install an event filter, paying attention to mouse events and looking for the move event, or you can inherit from QWidget and override the mouse event, looking for mouse move events.
http://doc.qt.io/qt-4.8/qwidget.html#mouseTracking-prop
http://doc.qt.io/qt-4.8/eventsandfilters.html
http://doc.qt.io/qt-4.8/qmouseevent.html
If you are ever in a situation when you don't need actual tracking, just position at the moment, you can use QCursor::pos().