Movable objects around a wxPanel - wxwidgets

In wxWidgets, I would like to have 2 objects on a wxPanel joined by a line and with a mouse down event to relocate the position of either of the 2 objects (The line should automatically be redrawn to follow the new position of the objects). I have tried using wxPaintDC to draw the initial position of the 2 objects (Custom created with mouse click events) and using dc.DrawLine to join these 2 objects together with a line. How should I proceed to allow make those 2 objects movable (mouse down event) along with the line? Can this even be achieve?

Of course it's possible (just about everything is, it's "only" a matter of effort), but it's not completely trivial and you may want to use OGL which does it for you. On the flip side, OGL is very old and completely unmaintained since a long time, so if your needs are really simple, it's probably still better to do it yourself.
If you do, here are some hints:
For mouse handling, you first need an (efficient if possible) hit testing function.
Once you have it, it's easy to detect where a click happens and what object is under it and start moving it if it makes sense. To be more user friendly, the move shouldn't start immediately, but wait until either the mouse moves a little, or stays pressed for some longer time (this will avoid accidental moves).
When the user is dragging the mouse you will get wxEVT_MOTION events. Use wxMouseEvent::Dragging() in your handler to check whether any mouse button is pressed.
Whatever you do, you must always draw from your wxEVT_PAINT handler, i.e. if an object moves, you must not redraw it immediately, but update its position, invalidate the area taken by it before and after the move (invalidating everything is simpler, but less efficient) and draw it from your OnPaint().
You want double buffering to avoid flicker, see wxAutoBufferedPaintDC

Related

How to click through elements?

I have two shape at same position, not same color, and when i click over them, i want to fire click event on both, not just the first.
These two shapes are in the same container.
I have tried getObjectsUnderPoint() under stage.on("mousemove"), but this function increase my FPS (60 to 32~, and inside there are just a console.log), So it's not a good solution.
I tried the bubble, the useCapture, but i think it isn't what i want.
I just want to fire click on all element behind my mouse.
If someone have a solution, please.
There are a few points here:
EaselJS objects sort of work like HTML DOM Elements. If an element has a mouse handler on it it will block objects in other hierarchies below it from receiving the event. This is just how it works. The main difference is that if you don't have mouse events, then they are just ignored (like if you set the pointerEvents on an HTML element to none to have the mouse ignore it).
Your idea with getObjectsUnderPoint is what I would have recommended. Running any hit-test logic on mousemove is going to be expensive (mousemove fires a LOT, which is why we give the ability to throttle the typical mouseover check if you enableMouseOver on the stage).
A few things to optimize it:
Ensure you are using mode=2 on your getObjectsUnderPoint, which will only check objects with mouse listeners. This greatly reduces the overhead in checking. [docs]
Instead of checking the stage on your own mousemove event, set a flag to check it on tick. This throttles it to your Ticker FPS at least. You could also set an interval to check it even less often. It can create a little bit of a visible lag, but you can probably find a nice balance.
Reduce what is checked. If you have a container with your clickable elements in it, you can only check that object for mouse interaction.
If your objects are the exact same, you can also just trigger the click manually on the second item.
obj1.on("click", function(event) {
obj2.dispatchEvent(event);
});
I hope those approaches provide you a solution. Let me know if you have follow-up questions.
Cheers,

CreateJS pressup/click won't trigger when target movie is played on mousedown/pressmove

I have a project where I need to make flash movie as an interactive game. Because, flash is already (or soon will be) obsolete for most of browsers, I've decided this game must be based on HTML5/JS. Because most of the graphics and animations are already done in this Flash movie (and I have its source), I'm developing it using Adobe Flash and CreateJS technology (HTML5 + Canvas + JS). So far, I like this solution pretty much, though I have an issue which I could not solve yet.
The game is a simple drag&drop matching game. The problem I have is shortly described in the question title and I will try to explain it here more detailed:
label.on('mousedown', function() {
//this.image.bg.gotoAndStop(2);
});
label.on('pressmove', function(evt) {
this.x = getStageX(evt.stageX);
this.y = getStageY(evt.stageY);
currentStage.setChildIndex(this, currentStage.getNumChildren() - 1);
stage.update();
});
label.on('pressup', function(evt) {
console.log('Hi! I'm mouseup event!')
this.x = labelInitX;
this.y = labelInitY;
this.image.bg.gotoAndStop(0);
});
Above, you can see simplified 3 event handlers I use. Everything is working fine until I uncomment second line - //this.image.bg.gotoAndStop(2);. When I do this, the pressup event does not trigger mostly, which is rather strange, because some times it does trigger (2-3 times out of 10), so the label sticks with the pointer until I press the button again.
Is this some bug or I simply does not understand something about the CreateJS and its event handlers. I tried different combinations of this. Used click instead of pressup, placing this.image.bg.gotoAndStop(2); inside the pressmove handler. Replacing pressmove handler with the stage.on('stagepressmove', handler). None did not work. this.image.bg.gotoAndStop(2); - this thing simply updates the timeframe (change the background image of the label). I do can change this image programatically (without playing timeframes) and I'm almost sure that the issue will be fixes, though I'd like to understand for myself what is wrong here or what I'm doing wrong with the event handlers.
Another, less important thing, but would be useful to know is why when pressmove event is running, the CreateJS objects stop receiving event triggers about rollover or mouseover? In DOM, by default event bubbling is working until you stop it with stopPropagation. How does it work here with CreateJS? Seems that bubbling is simply turned off here by default. How can I turn it on?
I thought I might shed some light on what I think is going on.
The normal mouse events "click", "mouseup", "rollover", "rollout", etc all function by the stage determine what the "target" of the mouse event was by default the target is the lowest-level thing that is interacted with. If you contents change while the mouse is down, it will not count as the same target when the mouseup occurs. Since positions are not re-checked without moving the mouse, the mouseover, mouseout, rollover, and rollout events may function oddly as well.
Conversely, the "pressmove" and "pressup" events do not care what is under the mouse once something is pressed. The target will always be what was pressed, which allows you to move the mouse out of the object (or even remove it), and still receive events from it. This also ensures that you receive a pressup event even if you release outside the object.
As #RandyPrad mentioned, the hitArea may solve your issue. By specifying a hit area, you are overriding the contents of your clip, so your target should always be the container (MovieClip) instead of its contents. That way no matter what is pressed inside the movieclip, it is the same target when you release. You can also get the same effect using the mouseChildren property.
movieClip.mouseChildren = false;
Hope that helps!
Please check your hit area of the button.
i think that your are playing image inside the btn is animating
please use this link http://www.createjs.com/tutorials/Mouse%20Interaction/hitArea.html

Overlay in wxWidgets

I need a control
It should be asynchronous (should not block the launching thread).
It should block all the user interactions with background screen.
Backdrop shadow on background so that it gives the feeling of disabled interactions with background.
I tried wxBusyInfo. It solves my first requirement, but one can interact with background window.
Then I use the wxWindowDisabler with wxBusyInfo, It disables the background window. But looks like events are getting buffered while disabler is on and when I am destroying wxWindowDisabler object, buffered events are firing.
Then I found wxEventBlocker that can be used to block the events.
Is this the right way to achieve the requirements?
wxBusyInfo is the right class to do what you want, it doesn't dispatch events, so I'm not sure how do you manage to interact with anything while it is shown. Because it doesn't dispatch events -- even the repaint ones -- it's not recommended to show it for relatively long periods of time. If you need something more permanent, use wxProgressDialog.
Finally, wxEventBlocker is a rather special class which is only useful in very specific circumstances and this is not one of them.

Core Data undo background thread deletion

I'm developing sort of a drawing app in which the user sets points on a canvas. What's being drawn gets stored as NSManagedObjects. I also enabled the undo manager so the user can undo the last drawing gestures by pressing a button.
It all works as expected.
Then I have a button to delete everything on the canvas (clear canvas). When pressed I make the deletion operation on a background thread cause it might take a while and I want to present a progress bar. Then I merge the background thread's model object context with the main thread's one. This works fine too.
But I would like to be able for the user to undo the complete deletion operation with just one tap on the undo button. This is what I'm unable to do.
For the multithreading part I'm following this tutorial: http://www.cimgf.com/2011/05/04/core-data-and-threads-without-the-headache/
It seems I can't get this to undo beyond the merge of the two threads (it worked once, though, I don't know why). Don't know if I'm supposed to nest the whole thing in undo groups. I have tried but still no luck.
I believe you can do it with nested undo groups.
Wrap your operation and merge between
-(void)beginUndoGrouping;
-(void)endUndoGrouping;
... and use -(void)undoNestedGroup to undo.

How to make an object invisible at a particular keyframe without moving it in Blender (2.59)?

I'm quite new to blender, and I'm doing some experiments with it.
I've been searching for a way to make an object disappear from sight at a particular key-frame, without moving it out of the camera view. E.g. at frame 1, cube is there, at (0, 0, 0) and at frame 2, it's not visible anymore, but still there at position (0,0,0), at frame 3 it gets visible again.
After searching the web, I came upon this page which suggests to move the object to another layer, but since it applies to blender 2.49, it seems the software has changed since then: I'm unable to find the 'Layer' option when inserting a key-frame.
I've found some other sites but either they suggest to use a technique similar to the one linked above, or they suggest to change the alpha of the texture, which I'm not interested in.
So, what's the preferred method to make an object invisible in blender 2.59?
Additional information (not relevant for the answer I'm expecting, IMO):
I'm using blender to make models for Unity.
I'm using 2.59 because that's the one that works with the unity version that I have.
There are lots of ways to achieve this effect.
The easiest way is to keyframe the visibility of the object.
To do this, you simply go to the outliner, and click the little eyeball next to your object name, then hover over the closed eyeball and hit "i" to keyframe. The eye will then turn yellow to indicate it's keyframed. Do the same with the camera icon (so that your render behaves the same way). Then go to the point where you want the object to appear, and click the eyball and camera again to make them reappear, then hit "i" again over each to keyframe them... Isn't blender a wonderful program? I love being able to keyframe just about everything! :D
There are also these less easy, but variously useful methods, which you may also use in case you want some sort of transition in your vanishing/appearing:
My perferred way is to just move the opbejct off the screen, keyframe position, then set the animation (in the Graph Editor) curve type to "constant" (Key -> Interpolation Mode -> Constant), and move the object into place and set the keyframe where you want it to appear. It will thus instantaneously appear.
Set the material properties of the object to Transparent, and choose "Z-Transparency" and set alpha to 0. Then simply keyframe the alpha (hover mouse over Alpha value and hit "i"), then go to where you want it to appear, change the alpha value to 1, and keyframe again. This will make it fade in over time, or you can change the curve to constant in the Graph editor, as described in method 1.
If you want to mask the object while it is still in place, you could make a cube around it, set the cube material transparency to "mask", and then move the cube off camera to unmask the object, rather than moving the object. This is handy for when you want to partially unmask something in the course of the animation. For example, if you are creating a text overlay for a video, where you want text to appear as if it's coming out of your hand, you can animate the masked object to follow the contour of your hand as it pulls away to reveal the text.
In Blender 2.65, you can animate the objects visibility toggle in your Outliner panel.
Next to your scene objects there will be three icons: an eye, a cursor, and a camera.
Follow these steps to animate viewport visibility:
Find the object you wish to animate in the Outliner Panel
Mouse over the eye icon and hit "i" on your keyboard to set a keyframe.
Go to the next frame and turn the eye off, then hit "i" moused over it again.
Do the same thing with the camera icon to animate render visibility. I will usually keyframe both the viewport and render visibility icons in tandem so as not to forget to have these toggled when its time to render.
In version 2.9 the eye icon cannot be used to set a keyframe. I've found the best way for me is to use the Object Properties tab and under Transform set the three scale values (X,Y,Z) to zero for invisibility. You can then click the diamond to the right to set the keyframe. To make the object re-appear return the scale values to their original and click on the diamond keyframe icon again.
Obviously you can make it a lot easier for yourself by applying scale to the objects first then just switch them between 0 and 1.
AFAIK there is no easy way to directly set an object invisible in your case. Although the visibility can be animated in Blender (in outline view mive your cursor on the eye and press i) Unity3D doesn't recognise it.
Possible workarounds:
Move it to (1000, 0, 0)
Scale it by a very small value
A more elaborated approach could be to use a driver like when turning FK/IK animation on and off dynamically via a variable.
I found out (today!) that, in Blender 2.8 (& presumably beyond), you can control visibility of objects in animations either in viewports and/or renders. Select the object and, in the Object Properties, open the Visibility section. You will see a dot beside the Viewports and Renders options. Click on the dot in either Viewports or Renders (or both). The relevant boxes should turn green. Either make the object visible or invisible by checking or clearing its box and then click 'i' to insert a keyframe. Repeat the process in other keyframes.
Another way to do this is to make a cube around it and add a boolean modifier to the object you want to disappear, set the operation to difference and select the cube as the modifier's object target. Then turn off the cube's visibility and animate the visibility of the modifier.