Qt QLabel border size - size

I have a label which has border around, it was set by this function:
this->setStyleSheet("border: 1px solid black");
but when I wanned to change position of the label I had to also give width and height of the border but where do I get it from?

In fact the parameters might be obtained via this->style(); that returns a pointer to QStyleSheetStyle... then via renderRule() one could get QRenderRule that stores all the structures required. The only problem is that those methods are private and intended for internal use.
So the simplest way is to use RegExp:
QRegExp regexp(".*border: *(\\d+)px.*");
if (regexp.indexIn(btn->styleSheet()) >= 0)
qDebug() << regexp.cap(1);

Related

change CAMetalLayer background color

My CAMetalLayer background color is black, even if i'm assigning new color as the backgroundColor property.
Am i missing something? Thanks!
Link to the original project :
https://github.com/audiokit/MetalParticles
This project takes a rather unconventional approach to clearing the drawable's texture each frame: it replaces the textures contents with an array of zeros that is the same size as the texture (width * height * 4). Subsequently, it encodes some compute work that actually draws the particles. This is almost certainly not the most efficient way to achieve this effect, but if you want to make the smallest change that could possibly work (as opposed to experimenting with making the code as efficient as possible), Just fill the blankBitmapRawData array with your desired clear color (near line 82 of ParticleLab.swift).
I have gone through your code and can not see a place where you are setting background Color.
The metal layer is added as a sublayer to it, so you have to set it explicitly.
Add this line at the end of your init method in ParticialLab class and see if it works.
self.backgroundColor = UIColor.redColor().CGColor
I found that self.isOpaque = false was needed on the layer.

width/height ratio preserved after a call to qtextimageformat.setWidth()?

In order to insert an image in a QTextDocument I have to modify its width and its height and to keep the original image's ratio. Hence my code :
qtextimageformat.setWidth( new_width );
cursor.insertImage( qtextimageformat, position )
I thought it was mandatory to modify the width and height but I was surprized to see that the call to .setWidth() somehow preserved the image's ratio, as if .setHeight() was implicitly called with the right parameter.
Is this the expected behaviour ? Or I am missing something ? The documentation didn't help me.
This is expected behavior, even if it is not explicit in documentation. The static functions QSize getImageSize(QTextDocument *doc, const QTextImageFormat &format) and QSize getPixmapSize(QTextDocument *doc, const QTextImageFormat &format) in qtextimagehandler.cpp automatically deduce the height if only width was specified in QTextImageFormat (and the opposite too)

Dynamic resizing of the body (LibGDX)

I have a circle-shaped dynamic body and I need to resize it during the game (It appears like a point, then it grows to a circle and after that it starts moving). How should I do that?
I have an idea - it's to use some animation (Circle has the same radius, but due to animation it looks like the circle grows), but I'm not sure if it's right way or not. (Besides I don't know how to realize it)
For scaling circle, if you are using sprite just scale it sprite.setScale(float), if your sprite is attached to Box2d Circle-shape then get the Body's shape and set the radius
Shape shape = body.getFixture().getShape;
shape.setRadius(radiusValue);
and if you are using ShapeRenderer just multiply the points of ShapeRenderer.
I assume that you are talking about a Box2D body.
It is not possible to change a circle-shaped fixture with Box2D. Box2D is a rigid body simulator. What you would have to do is destroy the fixture and replace it with a smaller/bigger version of the circle. But this will cause a lot of problems, since you cannot destroy a fixture when there is still a contact for example.
It would be better to keep the circle the same size and just simulate a change in size with an animation of a texture on top.
If you cannot simulate that, then maybe try the following approach: Have several versions of that circle in different sizes and keep them on top of each other. Implement a ContactFilter which will only cause contacts for the one circle which is currently "active".
Inside any Object class with box2d, I use the following for dynamic resizing:
public void resize(float newradius) {
this.body.destroyFixture(this.fixture);
fixtureDef.density = (float) (this.mass/(Math.PI*newradius*newradius));
this.radius = newradius;
CircleShape circle = new CircleShape();
circle.setRadius(newradius);
this.fixtureDef.shape = circle;
circle.dispose();
this.fixture = body.createFixture(fixtureDef);
this.fixture.setUserData(this);
}
You can also see the following topic: How to change size after it has been created

Two NSTextFields with interdependent widths in autolayout

I’m trying to put together what seems to be a simple case of two NSTextFields with dynamic width and fixed spacing in between. I cannot figure out an effective way to do so though.
I’m looking to get something like this:
The blue boxes are the NSTextFields. When more text is entered into one, it should grow and thus make the other one shrink, maintaining the lead space, trailing space and the spacing in between the fields. The first one should take the priority if both of the fields have too much text. Each field will also clearly have a maximum and a minimum possible width it can reach.
How would I go around handling this, preferably utilising IB autolayout as much as possible?
It seems to me that all of constraints you mentioned directly translate into interface builder --
First view has width >= something.
First view has width <= something
Same for Second view.
Space between views is fixed.
Second view wants to be as small as possible (have its width at 0) but this has lower lower priority than the previous constraints and lower priority than inner content size constraints.
The code I had to add to my view controller, after applying the constraints as per the ilya’s answer:
In controlTextDidChange (_controlWidthConstraint refers to the fixed width constraint of the input; it’s probably 0 by default for the second input):
// Get the new width that fits
float oldWidth = textControl.frame.size.width;
[input sizeToFit];
float controlWidth = textControl.frame.size.width;
// Don’t let the sizeToFit method modify the frame though
NSRect controlRect = textControl.frame;
controlRect.size.width = oldWidth;
textControl.frame = controlRect;
_controlWidthConstraint.constant = controlWidth;
The key lies in invalidating the intrinsicContentSize for the text field when text is input.
You can check a sample project here, to get you on the right track.

Zedgraph textobj X location depends on text length?

I have a Zedgraph textobj which I want to place always in the same x, y position (ASP.NET image). I noticed that the text doesn't always show in the same starting x position. It shifts depending on the text's length. I tried to have the text to have the same length by padding it with spaces. It helped a little but the result is not always consistent. I am using PaneFraction for coordType.
What's the proper method to have a piece of text to always show in the same x position. I am using textobj as a title because the native title property always shows up centered and I need my title be left aligned to the graph.
No, it does not depend on text lenght, however...
It depends on various other things:
Horizontal and vertical align of the text box (see: Location )
Current size of the pane. The font size is scaled dynamically to fit the changing size of the chart.
Counting proper positions to have TextObj (or any other object) always at the same place is quite hard. So you need avoid as much as you can any numbers/fractions in your location coordinates. ZedGraph sometimes calculates the true position in quite odd way then.
You haven't provided any code, so it's hard to tell if and where you made the mistake (if any). But, if I were you, I would do something like that:
TextObj fakeTitle = new TextObj("some title\n ", 0.0, 0.0); // I'm using \n to have additional line - this would give me some space, margin.
fakeTitle.Location.CoordinateFrame = CoordType.ChartFraction;
fakeTitle.Location.AlignH = AlignH.Left; // Left align - that's what you need
fakeTitle.Location.AlignV = AlignV.Bottom; // Bottom - it means, that left bottom corner of your object would be located at the left top corner of the chart (point (0,0))
fakeTitle.FontSpec.Border.IsVisible = false; // Disable the border
fakeTitle.FontSpec.Fill.IsVisible = false; // ... and the fill. You don't need it.
zg1.MasterPane[0].GraphObjList.Add(fakeTitle);
I'm using ChartFraction coordinates instead of PaneFraction (as drharris suggests) coordinates to have the title nicely aligned with the left border of the chart. Otherwise it would be flushed totally to the left side (no margin etc...) - it looks better this way.
But make sure you didn't set too big font size - it could be clipped at the top
Are you using this constructor?
TextObj(text, x, y, coordType, alignH, alignV)
If not, then be sure you're setting alignH to AlignH.Left and alignV to AlignV.Top. Then X and Y should be 0, 0. PaneFraction for the coordType should be the correct option here, unless I'm missing your intent.
Alternatively, you can simply download Zedgraph code, edit it to Left-align the title (or even better, provide an option for this, which should have been done originally), and then use it in production. Beauty of open source.