910209 - Where's ResizeEnd event?

[hamidi]

hi
i need to know when resize ends in my Silverlight application. how can i do that?

[RhysW]

Could you not use the FrameworkElemen t.SizeChanged Event? it is called multiple times each time it is resized but is also called for the very last resize event.

This MSDN explanation might be better

Additionally the SizeChanged Event handler may be what you are looking for MSDN link for more information about this one

[hamidi]

thanx 4 the reply, but i need a way to distinguish between multiple resize events coming and the last one. how can i realize this is the last resize and the user has ended resizing and has released the left mouse button? i need to know when this is triggered. the other resize events is not useful for me. i want to get only one resize event, the last one, every time user resizes the browser window.

[RhysW]

then the only solution i can think of it storing the size of the form or whatever, and everytime the mousebutton is released check to see if the size is different from the stored values, if it is store the new values for future comparisons and fire the rest of your code, i dont think there is an event that does exactly what you ask so you will have a hard time finding it unless you write something that does it for you. the event you are looking for is very specific and likely to be hard to find,

if you explain Why you need to know when its finished perhaps we can provide an alternative, but with the limited information were given its hard to suggest anything but whats already documeted, which apparently isnt what you need. though i appreciate sometimes you cant give away all your code sometimes its a lot of help to us all to be given an example, even if it is in pseudo code, is there a reason your code should only be fired on the final size changed event? or is it just you being picky about when it is fired?

[hamidi]

ok, let me explain the reason;
i'm showing a map inside browser. every time size is changed a request is sent to server for new map. it's not still optimized to just return the exposed part to the client. i send the whole image every time a request is received from client. this causes expensive resources to be consumed for nothing, while just the new size is important, the size which user is going to reach by mouse and have to generate several resize events. i want client send the last size to server and update the image at the end of resize.
about ur suggestion, unfortunately it's impractical, because i can't realize when mouse left button is released, because it appears in browser and browser events don't come to Silverlight applications' UserControl and their children.

[RhysW]

hmm, as i can't find a solution to this and no-one else on the other sites youve posted seems to know, might i make a suggestion to how to do this?

When the user finishes resizing the window you want to fire off and get a new map presumeably to fit in the windows new size correct? but what if the user only moves it a millimeter, perhaps by accident (which i do alot when im moving the mouse about) you arent going to want to send off for a new map then, especially if the map refreshes everytime its sent back the user would lose their location which would annoy them, not something you want for a customer product.

However you could use one of my solutions with a bit of tweaking, use one of the oens that checks if its resized, even if it fires off multiple times, BUT heres the trick, inside that event stick an if statement, ONLY send off for a new map at certain milestone sizes, e.g 1000 by 800px or 250 by 400 px (yes these sizes are stupid but its an example) if one of these milestones is breached send off for the map that will fit inside it, because lets face it if a user does only move the border by a small amount (a mm or 2) adjusting the map to by 2mm larger will hardly make any difference visually, and sending off for a new map thats 1mm larger is just silly if you ask me. (if youre having multiple milestones which i suggest then perhaps use a switch statement instead where CASE is using the length and height, if you just use multiple if statements then 400 x 400 would pass at 100x100 and get a map then pass at 200x200 and get a map then pass at 300x300 and egt a map, there would be three useless map calls, (unless your ifs also checked it was BELOW the next thresh-hold too) just a thought for you, perhaps just temporary until someone finds the proper way of doing it.

[hamidi]

thank u 4 ur suggestion
as far as i could understand, u mean i change the map size in grids of a value eg. 100 and if map size (width or height) gets different than before more than this value this causes me to send the request, right?
if so, i should choose a value which is not so small and not so big. if the value be large, the map is not got at expected values and if it be small, requests grow.
seems a good suggestion, but i doubt they agree (i work for a company). besides, the users are accurate in missing even such a neglectable margins. they expect when they maximize the browser window they get as large as map they can.
another method which i thought about was using a timer. if in a specified amount of time no resize occurred, then i decide to assume that resize has ended, and then send the request. in another words, i may wait for the new size to get stable. this reduces the number of resize events noticeably. but it's not as good as if i may know when the resize really done.
let's not surrender yet and think about another method i'm thinking about. may this help.
please take a look at:

http://www.codeproject.com/Questions/375951/910211-onmousedown-is-not-triggered

just if i may grab "onmouseup" , i may think i've found a solution. don't u think so? :)

[RhysW]

found you a solution, well, if you are happy with using javascript i have found you a solution! i found an answer on stack overflow, some javascript that uses your idea, it sees if ther is another change in size within 500ms of the last resize event, if not it updates the width and height textbox areas, but im sure you will be able to use it instead to resize the map, here is both a link and the code incase the question is deleted:

$(window).resize(function() {
    if(this.resizeTO) clearTimeout(this.resizeTO);
    this.resizeTO = setTimeout(function() {
        $(this).trigger('resizeEnd');
    }, 500);
});
You could have this is a base file somewhere, whatever you want to do...then you can bind to that new resizeEnd event you're triggering, like this:

$(window).bind('resizeEnd', function() {
    //do something, window hasn't changed size in 500ms
});

all this from Here

[hamidi]

thanx 4 ur favor,
as i said, timeout is a way like the grid way u suggested which hides unavailability of mouse up event. we will reach there in case we can't really find a solution to grab mouse up on the browser window's border. until then, i prefer not to use timeout and really find out when user releases the mouse left button. the way in the stackoverflow is just a simulation and ResizeEnd is not really received.
so let's concentrate again on the question i posted in codeproject link. someone has answered that this is not the event of the browser window. instead the handler is called because the client area is also resized and this is the client area's event that was raised. if so, there must be a way to access the browser window, its parent. is there a way?

[RhysW]

according to the link i gave you there isnt a way to know when the browser is finished resizing, because "Remember the event doesn't really start or end, it just "happens" when a resize occurs" this is the logic of browser resizing, it doesnt need to know if the user is finished or not so there is no event for it, so the only way to know is if you write your own method for deciding if a resize is done, and a timer is a way to decide if it is finished or not, unfortunately there isnt a finish clause for the browser resize, it just resizes to co-ordinates repeatedly, think of it this way, when you resize the window it follows the mouse fluidly, not stays still til the mouse is released, because the resize event happens continuously, as there is no resizeend event for a browser


EDIT: read the coments on the timeout answer in stack overflow, many people agree there just is NO end event for resize, YOU have to determine when a resize session has finished

EDIT 2: http://www.quirksmode.org/dom/events/resize.html

this url explains when and how many resize events are triggered in each browser, if youre using win xp you can make each one (cept IE ofc ¬_¬) fire only when finished, but that would be a choice of the user and only for xp, so your timer idea seems to be not just the only way but the best way

[hamidi]

u know, i hope we've thought right. if someone from Microsoft core members was asked, he could make us more certain about it. i wonder why browser must neglect WM_EXITSIZEMOVE while we've ResizeEnd in a form application?!
THEN, since i'm essentially a low-level programmer recently ported from C++ to C# and .Net, i'm thinking about a way to grab the original WM_EXITSIZEMOVE message. is there any WndProc in Silverlight? maybe i have to write an unmanaged low-level C++ code. i don't mind. just give me a possible way, and i will do my best for resolving this problem.