I'm having problems getting Pango Cairo to word wrap. Below is some demo code. I am setting the layout's width to the same as the red rectangle, so I would expect it to wrap to the red rectangle. As it is, it is simply putting one word on each line, as though the width was set very small. If I use pango.WRAP_WORD_CHAR, I only get one character to the line.
What am I doing wrong? How do I get the layout to wrap to the width I specified?
EDIT If I set the width to 100000, the words wrap correctly. This implies that the set_width and the construction arguments are using different units. Any ideas?
# -*- coding: utf-8 -*-
import sys
import cairo
import pango
import pangocairo
SIZE = 200
HALF = 100
QUARTER = 50
surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, SIZE, SIZE)
context = cairo.Context(surface)
context.set_source_rgb(1, 0, 0)
context.rectangle(QUARTER, QUARTER, HALF, HALF)
context.fill()
context.set_source_rgb(1, 1, 0)
context.translate(QUARTER, QUARTER)
pangocairo_context = pangocairo.CairoContext(context)
layout = pangocairo_context.create_layout()
layout.set_width(HALF)
layout.set_alignment(pango.ALIGN_LEFT)
layout.set_wrap(pango.WRAP_WORD)
layout.set_font_description(pango.FontDescription("Arial 10"))
layout.set_text("The Quick Brown Fox Jumps Over The Piqued Gymnast")
pangocairo_context.update_layout(layout)
pangocairo_context.show_layout(layout)
context.show_page()
with file("test.png", "w") as op:
surface.write_to_png(op)
I found the answer. The value must be multiplied by pango.SCALE. This doesn't seem to be mentioned in the documentation for the function in the C API.
Related
If I create a Label in a 500x500 area with wordwrap, how can I find out the height of the wrapped text ? I'm looking for the yellow height, not the salmon height.
Answer of #idrise doesn't work for system font And here I give a more flexible answer.
Assume we want to create a text/label which has a fixed width, but dynamic height according to text's length. for that you can use below code:
Label *lbl = Label::createWithSystemFont("aaa aaa aaa aaa aaa aaa", "Arial", 50);
lbl->setDimensions(FIXED_WIDTH, 0); // "0" means we don't care about wrapping vertically, hence `getContentSize().height` give a dynamic height according to text's length
////
auto dynamicHeight = title->getContentSize().height; // According to text's length :)
And obviously for fixed height you can do similarly.
Hope Help someone :]
This may seem a little counter intuitive.
First you set the dimensions with an excessively large height.
Calling getLineHeight and getStringNumLines will calculate the height based on the width passed.
You send the width and height back to setDimensions.
Now your labels getContentSize() will return the actual size of the text.
IE
label->setDimensions(width, 2000);
label->setDimensions(width,label->getStringNumLines() *
ceil(label->getLineHeight()));
They added the functionality you want:
Added three overflow type to new label: CLAMP, SHRINK, RESIZE_HEIGHT.
Overflow type is used to control label overflow result, In SHRINK mode, the font size will change dynamically to adapt the content size. In CLAMP mode, when label content goes out of the bounding box, it will be clipped, In RESIZE_HEIGHT mode, you can only change the width of label and the height is changed automatically. For example:
//Change the label's Overflow type
label->setOverflow(Label::Overflow::RESIZE_HEIGHT);
mTexto=Label::createWithTTF(mTextoHelp.c_str(),CCGetFont(), 30);
mTexto->setHeight(100.f);
mTexto->setOverflow(Label::Overflow::RESIZE_HEIGHT);
mTexto->setDimensions(mSize.width*0.8f, 0.f);
My code
VerticalText vt = new VerticalText(writer.getDirectContent());
vt.setVerticalLayout(marginLeft + squareHeight, 1191.0f - marginTop, squareHeight, 3, 20);
vt.setAlignment(Element.ALIGN_CENTER);
Paragraph p = new Paragraph(imgr.getText(), fontV);
p.setLeading(10);
vt.addText(p);
vt.go();
The result : Text is middle in vertical mode.
I want to display text is center in horizontal mode as below link:
How to solve this problem ?
As documented, left, center and right align has a different meaning in the context of VerticalText. Left is top, center is middle and right is bottom.
With class VerticalText, you always write from right to left. There is currently no way to align the text as shown in the screen shot to the right.
However, you could work around this problem by adding the vertical text in simulation mode first and then calculate the number of lines that have been written.
See for instance the VerticalText1 example from my book. I have adapted the code of that example like this:
BaseFont bf = BaseFont.createFont(
"KozMinPro-Regular", "UniJIS-UCS2-V", BaseFont.NOT_EMBEDDED);
Font font = new Font(bf, 20);
VerticalText vt = new VerticalText(writer.getDirectContent());
vt.setVerticalLayout(390, 570, 540, 12, 30);
vt.addText(new Chunk(MOVIE, font));
vt.go();
System.out.println(vt.getMaxLines());
vt.addText(new Phrase(TEXT1, font));
vt.go();
System.out.println(vt.getMaxLines());
vt.setAlignment(Element.ALIGN_RIGHT);
vt.addText(new Phrase(TEXT2, font));
vt.go();
System.out.println(vt.getMaxLines());
The output of the System.out calls is:
11
4
1
These numbers are the number of lines that are available after each go().
We start with 12 lines as defined in the setVerticalLayout() method.
We add MOVIE and there are 11 lines left. We've defined a leading of 30, which means we've already consumed (12 - 11) x 30pt = 30pt.
Then we add TEXT1 which is distributed over 7 lines, which take 7 * 30pt in width. In total we now have consumed (12 - 4) x 30pt = 240pt.
Finally we add TEXT2 which is distributed over 3 lines. Only 1 line is left. The total horizontal width of all the text is 330pt (we had only 30pt left).
Now that you know this math, you can execute the go() method in simulation mode, calculate the width that was consumed and use that info to add your text for real at the desired position.
When I try to set the line thickness of a table border, the result changes the line type to something undesired. Why is the line width parameter affecting the line style parameter? See the examples below and try them for yourself. I am using MS Office 2011 Word v14.2.3.
tell application "Microsoft Word"
set line style of (get border selection which border border bottom) to line width225 point
get line width of (get border selection which border border bottom)--test:results in line width150. Why? I just set it to line width225!
--width25 = fine dots
--width225 = cornered sine wave
--width50 = dashed line
--width75 = dash + 3 dots + dash
--width100 = 3 lines
--width150 = 2 lines
--width300 = single
--width450 = does not work
--width600 = does not work
end tell
If I run this on a table which has the settings that I want, in order to see what they are:
tell application "Microsoft Word"
get properties of (get border selection which border border bottom)
end tell
I get:
{class:border, visible:true, color index:no highlight, inside:false, line style:line style single, line width:line width225 point, art style:missing value, art width:missing value, color:{0, 0, 0}, color theme index:no theme color}
Which is correct. I should be able to copy those parameters to make my script work, but something happens when I try to set the line width (border thickness).
If you want to change the line thickness, use line width instead of line style, otherwise it's normal that it doesn't do what you expect.
set line width of (get border selection which border border bottom) to line width225 point
If you want to change the line style, you should use a value from this list : (
line style none, line style single, line style dot, line style dash small gap, and many more ...)
I have taken passing shots at learning Cairo in the past, but always moved on in favor of some other graphics library. My problem is that I can't find a good tutorial that gives me a simple display for my surface. I have always ended up digging through GTK or QT documentation about things that have nothing to do with what I want to do. I want to learn Cairo, not a massive OO architecture.
What is a bare bones wrapper to give me a cross-platform window with a Cairo canvas to draw on?
I have used cairo for virtually anything involving drawing. I work at a medical software company, so I prototype scientific data visualization and other things.
I have usually three ways to display my drawings:
A GTK drawing area created with a Python script and GTK;
A PNG image displayed directly on screen using Python Image Library show() method;
A PNG image saved to disk, also via Python Image Library.
A simple script derived from cairographics examples, which actually I use as a template for any new project, is:
import gtk
class Canvas(gtk.DrawingArea):
def __init__(self):
super(Canvas, self).__init__()
self.connect("expose_event", self.expose)
self.set_size_request(800,500)
def expose(self, widget, event):
cr = widget.window.cairo_create()
rect = self.get_allocation()
# you can use w and h to calculate relative positions which
# also change dynamically if window gets resized
w = rect.width
h = rect.height
# here is the part where you actually draw
cr.move_to(0,0)
cr.line_to(w/2, h/2)
cr.stroke()
window = gtk.Window()
canvas = Canvas()
window.add(canvas)
window.set_position(gtk.WIN_POS_CENTER)
window.show_all()
gtk.main()
Or if you prefer not to deal with GUI toolkits, you can create and display an image on screen, and optionally save it to file:
import cairo, Image
width = 800
height = 600
surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, width, height)
cr = cairo.Context(surface)
# optional conversion from screen to cartesian coordinates:
cr.translate(0, height)
cr.scale(1, -1)
# something very similar to Japanese flag:
cr.set_source_rgb(1,1,1)
cr.rectangle(0, 0, width, height)
cr.fill()
cr.arc(width/2, height/2, 150, 0, 6.28)
cr.set_source_rgb(1,0,0)
cr.fill()
im = Image.frombuffer("RGBA",
(width, height),
surface.get_data(),
"raw",
"BGRA",
0,1) # don't ask me what these are!
im.show()
# im.save('filename', 'png')
An answer to a related question demonstrates a very simple setup in Gtk2HS to draw on a drawingArea with Cairo.
import Graphics.UI.Gtk
import Graphics.Rendering.Cairo
main :: IO ()
main = do
initGUI
window <- windowNew
drawingArea <- drawingAreaNew
containerAdd window drawingArea
drawingArea `onExpose` (\_ -> renderScene drawingArea)
window `onDestroy` mainQuit
windowSetDefaultSize window 640 480
widgetShowAll window
mainGUI
renderScene :: DrawingArea -> IO Bool
renderScene da = do
dw <- widgetGetDrawWindow da
renderWithDrawable dw $ do setSourceRGBA 0.5 0.5 0.5 1.0
moveTo 100.0 100.0
showText "HelloWorld"
return True
Simply pass your Cairo animation routine to renderWithDrawable dw in renderScene.
I am using CoreText to render multiple columns of text. However, when I set the first letter of the 1st paragraph to a bold, larger font than the rest of the text, I incur 2 issues (both visible in the attached image):
The spacing underneath the first line is too big (I understand that this is because the 1st character could be a g,y,p,q etc.
Lines below the first line now do not line up with corresponding lines in the next column.
Any advice on how to overcome these 2 issues would be greatly appreciated, thank you.
According to the documentation kCTParagraphStyleSpecifierMaximumLineHeight should have solved the problem, but unfortunately does not seem to work at least on IOS 4.3.
CTParagraphStyleSetting theSettings[5] =
{
{ kCTParagraphStyleSpecifierParagraphSpacing, sizeof(CGFloat), &spaceBetweenParaghraphs },
{ kCTParagraphStyleSpecifierParagraphSpacingBefore, sizeof(CGFloat), &topSpacing },
{ kCTParagraphStyleSpecifierLineSpacing, sizeof(CGFloat), &spaceBetweenLines },
{ kCTParagraphStyleSpecifierMinimumLineHeight, sizeof(CGFloat), &lineHeight},
{ kCTParagraphStyleSpecifierMaximumLineHeight, sizeof(CGFloat), &lineHeight}
};
CTParagraphStyleRef paragraphStyle = CTParagraphStyleCreate(theSettings, 5);
To be fair documentation says it's available in OS v10.5 and later.
kCTParagraphStyleSpecifierMaximumLineHeight:
The maximum height that any line in the frame will occupy, regardless of the font size or size of any attached graphic. Glyphs and graphics exceeding this height will overlap neighboring lines. A maximum height of 0 implies no line height limit. This value is always nonnegative.Type: CGFloat.
Default: 0.0.
Application: CTFramesetter.
Available in Mac OS X v10.5 and later.
Declared in CTParagraphStyle.h.
It seems the only way to fix this is with a workaround, which is to create 3 frames for the first column,1 for the W, 1 for the rest of the first sentence and 1 for the rest of the first column.