Qt 5.x GUI 프로젝트를 새로 만들어서 빌드할 때 다음과 같은 에러가 발생한다면

추가 포함 디렉토리에 아래와 같이 추가하여 다시 빌드하면 정상 빌드된다.

$(QTDIR)\include\QtANGLE

Qt OpenGL 라이브러리는 추가하지 않아도 된다.

".QWidget {"
"background-color: rgba(0, 0, 0, 100%); }"

"QWidget {"
"background-color: rgba(0, 0, 0, 100%); }"

The Style Sheet Syntax

http://qt-project.org/doc/qt-4.8/stylesheet-syntax.html

Selector Types

All the examples so far used the simplest type of selector, the Type Selector. Qt Style Sheets support all the selectors defined in CSS2. The table below summarizes the most useful types of selectors.

Qt Style Sheets

출처: http://qt-project.org/doc/qt-5.1/qtwidgets/stylesheet.html

Qt Style Sheets are a powerful mechanism that allows you to customize the appearance of widgets, in addition to what is already possible by subclassing QStyle. The concepts, terminology, and syntax of Qt Style Sheets are heavily inspired by HTML Cascading Style Sheets (CSS) but adapted to the world of widgets.

Topics:

• Overview
• The Style Sheet Syntax
• Qt Designer Integration
• Customizing Qt Widgets Using Style Sheets
• Qt Style Sheets Reference
• Qt Style Sheets Examples

Overview

Styles sheets are textual specifications that can be set on the whole application using QApplication::setStyleSheet() or on a specific widget (and its children) using QWidget::setStyleSheet(). If several style sheets are set at different levels, Qt derives the effective style sheet from all of those that are set. This is called cascading.

For example, the following style sheet specifies that all QLineEdits should use yellow as their background color, and allQCheckBoxes should use red as the text color:

QLineEdit { background: yellow }
QCheckBox { color: red }

For this kind of customization, style sheets are much more powerful than QPalette. For example, it might be tempting to set the QPalette::Button role to red for a QPushButton to obtain a red push button. However, this wasn't guaranteed to work for all styles, because style authors are restricted by the different platforms' guidelines and (on Windows XP and Mac OS X) by the native theme engine.

Style sheets let you perform all kinds of customizations that are difficult or impossible to perform using QPalette alone. If you want yellow backgrounds for mandatory fields, red text for potentially destructive push buttons, or fancy check boxes, style sheets are the answer.

Style sheets are applied on top of the current widget style, meaning that your applications will look as native as possible, but any style sheet constraints will be taken into consideration. Unlike palette fiddling, style sheets offer guarantees: If you set the background color of a QPushButton to be red, you can be assured that the button will have a red background in all styles, on all platforms. In addition, Qt Designer provides style sheet integration, making it easy to view the effects of a style sheet in different widget styles.

In addition, style sheets can be used to provide a distinctive look and feel for your application, without having to subclass QStyle. For example, you can specify arbitrary images for radio buttons and check boxes to make them stand out. Using this technique, you can also achieve minor customizations that would normally require subclassing several style classes, such as specifying a style hint. The Style Sheet example depicted below defines two distinctive style sheets that you can try out and modify at will.

Coffee theme running on Windows XP	Pagefold theme running on Windows XP

Coffee theme running on Ubuntu Linux	Pagefold theme running on Mac OS X

When a style sheet is active, the QStyle returned by QWidget::style() is a wrapper "style sheet" style, not the platform-specific style. The wrapper style ensures that any active style sheet is respected and otherwise forwards the drawing operations to the underlying, platform-specific style (e.g., QWindowsXPStyle on Windows XP).

Since Qt 4.5, Qt style sheets fully supports Mac OS X.

Warning: Qt style sheets are currently not supported for custom QStyle subclasses. We plan to address this in some future release.

Styles The Style Sheet Syntax

frameless windows에 drop shadow 효과 주는 방법

원문 출처 : stackoverflow

http://stackoverflow.com/questions/12347776/how-to-put-a-shadow-to-a-frameless-window-in-qt

Q: How to put a shadow to a Frameless window in Qt

A: 

Add a "QWidget" (say widget) to the MainWindow and move everything that's on the MainWindow to the widget. Then do this:

setAttribute(Qt::WA_TranslucentBackground); //enable MainWindow to be transparent

QGraphicsDropShadowEffect* effect = new QGraphicsDropShadowEffect();
effect->setBlurRadius(5);
ui->widget->setGraphicsEffect(effect);

This seems to work for me. See:

	bool	loadFromData(const uchar * data, int len, const char * format = 0)
	bool	loadFromData(const QByteArray & data, const char * format = 0)

읽을 대상 이미지가 비트맵의 경우 해당 헤더 정보가 없으면 loadFromData 함수 사용시 결과가 실패 떨어진다.

다른 이미지 파일은 안 해봐서 모름.

이미지 파일을 읽어서 사용할 땐 문제가 없으나 resource dll에서 비트맵을 읽어왔을 때 문제 발생.

resource dll에 Bitmap Image를 추가할 때 헤더 정보가 빠지는 것 같다.

이럴 땐 리소스를 추가할 때 Bitmap으로 추가하지 말고 '사용자 지정 리소스' 타입으로 만들어서 추가하면 된다.

(.rc 파일을 직접 건드려야 할 것이야!)

widget의 윈도우 프레임을 제거하는 방법.

void SomeWidget::foo()
{
	setAttribute(Qt::WA_TranslucentBackground, true); // 배경 투명하게
	setWindowFlags(Qt::FramelessWindowHint); // 프레임 제거
}

QWidget 을 상속받는 widget에 모두 사용 가능하다?

안 해봐서 모름.

QPushButton에 이미지 올리기와 enter/leave/press/release event에서의 이미지 변경.

class button : public QPushButton
{
	...

	void setImage(QPiaxmap& _pixmap)
	{
		QSize size;
		size.setWidth(_pixmap.width() / 4);
		size.setHeight(_pixmap.height());

		m_icons[Normal] = (QIcon(_pixmap.copy(Normal * size.width(), 0, size.width(), size.height())));
		m_icons[Click] = (QIcon(_pixmap.copy(Click * size.width(), 0, size.width(), size.height())));
		m_icons[Highlight] = (QIcon(_pixmap.copy(Highlight * size.width(), 0, size.width(), size.height())));
		m_icons[Disable] = (QIcon(_pixmap.copy(Disable * size.width(), 0, size.width(), size.height())));

		if(isEnabled())	setIcon(m_icons[Normal]);
		else			setIcon(m_icons[Disable]);
	
		setIconSize(m_size);
		resize(m_size);
	}
	virtual void	enterEvent(QEvent* _event)
	{
		__super::enterEvent(_event);

		if(isEnabled())
			setIcon(m_icons[Highlight]);
	}
	virtual void leaveEvent(QEvent* _event)
	{
		__super::leaveEvent(_event);

		if(isEnabled())
			setIcon(m_icons[Normal]);
	}
	virtual void mousePressEvent(QMouseEvent* _event)
	{
		__super::mousePressEvent(_event);
	
		if(isEnabled())
			setIcon(m_icons[Click]);
	}
	virtual void mouseReleaseEvent(QMouseEvent* _event)
	{
		__super::mouseReleaseEvent(_event);

		if(isEnabled())
			setIcon(m_icons[Highlight]);
	}
	virtual void changeEvent(QEvent* _event)
	{
		__super::changeEvent(_event);

		if(QEvent::EnabledChange != _event->type())
			return;

		if(isEnabled())	setIcon(m_icons[Normal]);
		else			setIcon(m_icons[Disable]);
	}

};

와.. vector<QIcon> m_icons; 요거 쓸라니까 syntaxhighlighter에서 </qicon>을 붙여버리네 ㅡ,.ㅡ

버튼 이미지는 연속된 4개의 이미지가 하나의 파일로 제작되었을 때를 가정,

m_icons는 vector<QIcon>으로 size는 4로 미리 정의.

번거롭다.

char temp[MAX_PATH] = {0,};
::GetModuleFileNameA(NULL, temp, MAX_PATH);
QFileInfo info(temp);
QString workingDir = QDir::toNativeSeparators(info.absoluteDir().path());

QFileInfo를 통해 획득한 absoluteDir을 보면 경로의 구분자가 '\'가 아닌 '/'로 되어있다.

예) C:\Windows\System32    ->    C;/Windows/System32

이를 원래의 윈도우즈 경로로 변경하려면 QDir의 static 함수인 toNativeSeparators를 사용하면 된다!

국내 커뮤니티 : http://www.korone.net/qt.php

개인 블로그

구리님 : http://dgoh.tistory.com/category/QT

뻐그

https://bugreports.qt-project.org/browse/QTBUG-29109

기타

http://qt-project.org/wiki/Build_Standalone_Qt_Application_for_Windows

ICO Image Format

http://doc.qt.digia.com/solutions/4/qticoimageformat/

Stylesheet Example

http://qt-project.org/doc/qt-4.8/stylesheet-examples.html

how to set $(QTDIR) path in visual studio

http://smh0816.egloos.com/3362003