I have a string that I can paint in Core Text like so:
CGContextShowGlyphsAtPoint(context, 0, 0, glyphs, glyphCount);
Works great. Now I need to paint each of those glyphs individually, in the same spot as they would end up painted using that nice utility function above. And I'm not doing it in English, either...sometimes there is a glyph below a glyph below a glyph (diacritic).
Obviously I need something like this:
CGPoint pt = CGPointMakeZero;
for (int i = 0; i < glyphCount; i++) {
CGContextShowGlyphsAtPoint(context, pt.x, pt.y, glyphs[i], 1);
pt.x += <some quantity>
pt.y += <some quantity>
}
Unfortunately I haven't figured out what the "some quantities" are supposed to be yet...some combination of metrics fromCGContextGetAdvancesForGlyphs and/or CTFontGetVerticalTranslationsForGlyphs and/or CGContextGetGlyphBBoxes have been my first guesses, but I haven't got it to work yet.
Anyone have a solution/other ideas?
If you want a test string, try అక్త్రిన్.
(Background: I need to do the painting of glyphs one by one because of customizations to appearances to individual glyphs that I want to make in my app).
Way late to the party here but this question/answer combo shows how layout is calculated line by line then glyph by glyph.
Core Text calculate letter frame in iOS
Related
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.
I am developing an app, that has support for customizing fonts, colors etc. in design time.
You just swap a plist and the app has a different style,color,s etc..
This works, i need to have it like that . So far so good.
Some buttons have titles. I use two different custom fonts for two different builds.
The problem is, using the other font causes the titleLabels in all buttons to be offset 5 point to the TOP.
I can't use some "hacky "way to move the offset 5 px up. Since it wll coause the first font to be offset 5 px up.
I am not really sure if the problme is in my code, or in the source font file.
The label is centered horizontaly and verticaly. Is there any other way to generalize the code so that it would handle that offset difference?
compare like this:
CGSize firstStringSize = [myString sizeWithFont:firstFont]; //get size for first string with its font
CGSize secondStringSize = [myString sizeWithFont:secondFont]; //get size for second string with its font
if(!CGSizeEqualToSize(firstStringSize, secondStringSize)) //checking for both are not equal
{
if(firstStringSize.height > secondStringSize.height)
//secondStringSize offset 5 px
if(secondStringSize.height > firstStringSize.height)
//firstStringSize offset 5 px
}
I'm fairly new to wxWidgets so please bear with me. Let's say I have a 10Kx10K image and my wxScrolledWindow has a size of 640x480. I load the whole image into a wxBitmap which I use in my paint function.
Now in my OnPaint function I just say
wxPaintDC dc(this);
dc.DrawBitmap(_Bitmap, 0, 0 );
This somewhat works for the first few paints but soon the Window content is out order and artifacts appear. This happens very fast when I move a scroll bar back and forth very quickly.
I use the latest wxWidgets on a Windows 7 machine.
So, how can I improve my painting code?
Many thanks,
Christian
Using a 10000x10000 wxBitmap is a bad idea on its own, it may simply fail to be created on an older system (that's 400MiB of video RAM!). Drawing it entirely is sheer madness.
I don't know where does your data come from but in a typical case of e.g. a map to be shown on screen, you should break it into tiles, convert the tiles that are currently visible on screen to wxBitmap (or several of them) and draw only those.
Then you may optimize your drawing by using double buffering (which is relatively useless under Windows 7 that double buffers everything on its own) and otherwise, but you should be using a reasonably-sized backing store bitmap.
This sounds like something that might be helped by using double buffering.
The first thing to start trying is to replace wxPaintDC with wxBufferedPaintDC
For more suggestions, here is a wiki article on the subject: http://wiki.wxwidgets.org/Flicker-Free_Drawing
As Ravenspoint kindly pointed out, there is an article on wxWidgets' wiki. So according to that article two things need to happen. First override the EVT_ERASE_BACKGROUND with an empty function.
void Canvas::EraseBackground( wxEraseEvent& WXUNUSED(event))
{
}
And second to implement a basic double buffering scheme. Here is how I did it.
void Canvas::OnPaint(wxPaintEvent& WXUNUSED(event))
{
int x, y;
GetViewStart(&x, &y);
wxRect Client_Area = GetClientRect();
int width = Client_Area.width;
int height = Client_Area.height;
wxBitmap Current = _Bitmap.GetSubBitmap(wxRect( x * 10, y * 10, width, height ));
wxPaintDC dc(this);
dc.DrawBitmap(Current, 0, 0, false );
}
My scroll rate for both x and y is set to 10. That's why I multiply the view start coordinates.
Any more insight is very welcome.
Thanks,
Christian
I have designed my help page for my application,it contains some FAQs..so I have used UILabels for question and answer,I have adjusted,x,y,width and height exactly in the xib,leaving a gap between a question and answer and answer and next question.so totally I have some 10 question and answers,I have put them inside a scroll view.
But now, suppose the text changes dynamically, how can I adjust the positions and width and height,is a problem which I am not able to figure out, by using the below code,it adjusts the height and width of a particular label,if the text increases
NSString * test=#" It may come as a rude shock, but Facebook users should not feel surprised if tomorrow they come across their photos existing in the web world despite having deleted them personally long ago.";
m_testLabel.text = test;
m_testLabel.numberOfLines = 0; //will wrap text in new line
[m_testLabel sizeToFit];
but then, my next label will clash with it..is their any way so that all the labels get adjusted according if the width of any label increases or decreases?
Hope you all have understood my question..
Did you look into the below function, pass the font you have used and the size to which u want to constraint the label into.
- (CGSize)sizeWithFont:(UIFont *)font constrainedToSize:(CGSize)size
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.