I am writing a custom widget using gtkmm and I would like to use the standard selection colour when part of my widget is selected. For example when you select text in a text box, the background colour goes (for me) dark blue, so I want to obtain this same dark blue colour.
I have tried this, but I only get black or white, not the actual colours in use:
bool MyWidget::on_draw(const Cairo::RefPtr<Cairo::Context>& cr) {
Gdk::Cairo::set_source_rgba(cr,
get_style_context()->get_color(Gtk::STATE_FLAG_SELECTED));
}
What is the correct way to obtain the standard colours with gtkmm, such that if the user changes their colour theme, the changes will also be reflected here?
Or is it considered best practice to define some new CSS styles which inherit from the standard system ones, so that people can override colours for just my widget if they desire, without affecting others?
Turns out the answer to this is that what I was doing in the question was correct, except there were no styles applied to the widget so the colours were just black and white.
I had to add this in the widget's constructor:
this->get_style_context()->add_class(GTK_STYLE_CLASS_ENTRY);
To get text entry styles. Of course this made render_background() as suggested by ebassi render a text entry background instead, which isn't what I wanted (I just wanted a solid colour.) So instead I changed the above line (in the constructor) to:
this->get_style_context()->add_class(GTK_STYLE_CLASS_DEFAULT);
And in my render function, temporarily set text-entry styles just to get the colour:
auto cxStyle = this->get_style_context();
cxStyle->context_save();
cxStyle->add_class(GTK_STYLE_CLASS_ENTRY);
Gdk::Cairo::set_source_rgba(cr, cxStyle->get_background_color(Gtk::STATE_FLAG_SELECTED));
cr->fill();
cxStyle->context_restore();
This way I was able to obtain the text selection colour and fill a rectangle behind the area of my custom widget that should be shown as currently selected.
I couldn't use render_background() here because it would have drawn the background of a text control which I don't want, I just wanted a solid filled rectangle.
The proper way to render the background of a widget is to use gtk_render_background(). This function will take into account widget state and style.
Your code above becomes:
bool
MyWidget::on_draw (const Cairo::RefPtr<Cairo::Context>& cr)
{
double w = get_allocated_width(), h = get_allocated_height();
Glib::RefPtr<Gtk::StyleContext> context = get_style_context();
context->render_background(cr, 0, 0, w, h);
return true;
}
This way your widget will always be updated to reflect the theme.
If you want to control the color and style of your widget you should use an additional Gtk::StyleProvider for your application to load a custom CSS fragment with the desired style classes.
Related
I have a Aggrid and have to change the color of row and text from default blue and black to green and white when we select a row in Aggrid.
I tried making use of this, but the color of links in text does not change to white
It is not related to ag-grid. All you need is to add different CSS rule for links inside a selected row, to override link color (and also, probably, :hover, :active, :focus states).
.ag-row-selected A {
color: while;
}
I sometimes wonder what vscode's default widget color is. For example: when I use a github theme, I find that it only defines one part of the color internally, so where is the other part defined, and how do I view it.
For example, when I look at the color scheme of the topic by Developer : generator color theme... command, the undefined part is always shown in the form of comments(e.g "activityBar.activeBackground": null,). How can I see the color of this annotated section?
Using flutter inspector I'm not able to find a list of widget's properties like font size, font family, border color, padding, margin ...
For example, in a Text widget the available properties are textDirection, textAlign, size, and a few more, like in screenshot below:
I would like to see all computed properties, like browsers do:
Of course they are different tools, but i would like to know if there is a way to check more properties.
I also found a code-based solution, to access widget properties after it has been rendered, like in this question:
How to get the TextFormField text color,fontsize, etc using controller in flutter?
Is that the best way to achieve the result? Is it possible to use Keys in a way which allows to access widget properties without using a custom widget (i would like to save the reference to a Text, Row, etc. widgets and print all their properties)?
I also tried to use toDiagnosticsNode and toStringDeep methods as follows (_textWidget is of course a Text widget created above, this code is called when i click a button):
var test = _textWidget.toDiagnosticsNode().getProperties();
if (test != null && test.isNotEmpty) {
test.forEach((element) {
print(element.toStringDeep());
});
}
Is it possible to play a bit with a recursive function to get all the properties? All i can see with that code is the text displayed.
I am trying to find value for phClr, but no results.
Slide master is not having mapping for phClr.
I am aware that phClr is just a passed-in color value, but what exactly is its color reference?
Is it bg2 or anything else?
http://msdn.microsoft.com/en-us/library/cc964302(v=office.12).aspx
Blockquote
The scheme color value is set to placeholder color (the value phClr). This value appears throughout the fill, line, effect, and background styles and indicates that the settings are applied to the theme color applicable for a given style. This allows the same fill, line, and effect styles to populate across the theme colors that appear in the OfficeArt galleries.
“phClr” is a kind of placeholder color
I have a question related to eclipse plugin development. Is there any means
by which I can programmatically change the background color in eclipse.
I am able to change the text foreground color by calling
setTextColor(color, offset, length, controlRedraw) in ITextViewer
but I don't find any function by which I can change the background
color of the text.
If anyone has been through this kindly share your thoughts.
Thanks
arav
I am not sure this can be done easily, short of extending your own version of a Text Editor, here you provide a Configuration Class which inturn accepts a PresentationReconciler Class which is like a Rule Class that tells you if you need to put a Foreground or a Background Color
See this document
PresentationReconciler
IPresentationDamager: define dirty region given a text change
IPresentationRepairer: recreate presentation for dirty region
DefaultDamagerRepairer does both, based on a token scanner
ITokenScanner: parse text into a token stream
RuleBasedScanner uses simple rules
Extract from the presentation
From Text Editor Recipes, Season’s recipes for your text editor
Tom Eicher, IBM Eclipse Team
Here, the null background color means, takes the default system background for that widget. (so here: white).
But you could specify whatever color you want, based on the partitioning of your document and on the rules that would apply.
I know this was asked a while ago, but in case anyone is looking for another solution, I thought I would post the following:
Since you are able to use the setTextColor method, then you should be able to use the changeTextPresentation method as well.
In the case of my plug-in, I have a TextListener that calls the TextChanged method I overwrote. I did the following to add background color using the changeTextPresentation method. In doing so, I was able to get a Green background with Black foreground. Not that I would want this, of course, but just for testing purposes.
public void TextChanged(TextEvent event){
...
TextPresentation presentation = new TextPresentation();
TextAttribute attr = new TextAttribute(new ColorManager().getColor(MyConstants.BLACK),
new ColorManager().getColor(MyConstants.GREEN), style);
presentation.addStyleRange(new StyleRange(startOffset, tokLength, attr.getForeground(),
attr.getBackground());
sourceViewer.changeTextPresentation(presentation, true); //sourceViewer is a global variable passed to my TextListener class constructor.
}