make GUIUtil::ThemedLabel UI form friendly

jarolrod commented at 7:59 am on June 7, 2021: member

This allows the GUIUtil::ThemedLabel class able to be used in UI form files. This is accomplished by introducing a form file friendly constructor which only takes in a QWidget* parent.

You cannot pass in the platform_style when initializing a GUIUtil::ThemedLabel in a UI form file. This introduces a setPlatformStyle function to be able to pass in the platform_style at a later point.

Additionally; because we are not initializing the class with a platform_style, we need to implement a check in updateThemedPixmap so that it only executes when the m_platform_style has been set. A segfault would occur without this conditional as a ChangeEvent occurs on application start

This allows this class to be used in the form file for #330 for an elegant solution.

qt: make GUIUtil::ThemedLabel UI form friendly

This makes the GUIUtil::ThemedLabel class able to be used in UI form
files. This is accomplished by introducing a form file friendly
constructor which only takes in a `QWidget* parent`.

You cannot pass in the `platform_style` when initializing a
GUIUtil::ThemedLabel in a UI form file. This introduces a
`setPlatformStyle` function to be able to pass in the `platform_style`
at a later point.

Additionally; because we are not initializing the class with a
`platform_style`, we need to implement a check in `updateThemedPixmap`
to only occur when the `m_platform_style` has been set. A segfault would
occur without this conditional as a `ChangeEvent` occurs on application
start

f923b80a23

hebasto added the label UI on Jun 7, 2021

in src/qt/guiutil.h:249 in f923b80a23

245     protected:
246         void changeEvent(QEvent* e) override;
247 
248     private:
249-        const PlatformStyle* m_platform_style;
250+        const PlatformStyle* m_platform_style = nullptr;

luke-jr commented at 9:16 pm on June 12, 2021:

{nullptr}

luke-jr changes_requested

hebasto renamed this:
~~qt: make GUIUtil::ThemedLabel UI form friendly~~
make GUIUtil::ThemedLabel UI form friendly
on Jun 12, 2021

in src/qt/guiutil.cpp:800 in f923b80a23

792@@ -793,6 +793,11 @@ qreal calculateIdealFontSize(int width, const QString& text, QFont font, qreal m
793     return font_size;
794 }
795 
796+ThemedLabel::ThemedLabel(QWidget* parent)
797+{
798+    QLabel{parent};
799+}
800+

hebasto commented at 2:35 am on June 13, 2021:

0    : QLabel{parent} {}

in src/qt/guiutil.cpp:820 in f923b80a23

811@@ -807,6 +812,11 @@ void ThemedLabel::setThemedPixmap(const QString& image_filename, int width, int
812     updateThemedPixmap();
813 }
814 
815+void ThemedLabel::setPlatformStyle(const PlatformStyle* platform_style)
816+{
817+    m_platform_style = platform_style;
818+    assert(m_platform_style);
819+}
820 void ThemedLabel::changeEvent(QEvent* e)

hebasto commented at 2:43 am on June 13, 2021:

style nit: Add an empty line as a separator?

hebasto commented at 2:57 am on June 13, 2021: member

@jarolrod

I think we should adopt your suggestion on IRC to move the ThemedLabel into its own module for the following reasons:

all of so called “promoted widgets” in our repo have their own modules
see https://github.com/bitcoin-core/gui/pull/330/files#r650460316

Also, it seams reasonable to me to drop this pr, and review both commits in #330, because without actual usage of a promoted widget in a *.ui file it is not easy to test it.

jarolrod commented at 9:52 pm on July 5, 2021: member

This was meant to be a part of #330. A simpler approach was chosen for that PR and this is no longer worth the effort as the issue has been fixed.

Note: If there is ever a reason to make the ThemedLabel class UI friendly, the approach should be to do so in its own class file; moving it away from GUIUtil

jarolrod closed this on Jul 5, 2021

bitcoin-core locked this on Aug 16, 2022

make GUIUtil::ThemedLabel UI form friendly #358