Use better static icons for widgets in dark mode

src/appsettings.cpp

@@ -22,6 +22,8 @@
 #include <QSize>
 #include <QDir>
 #include <QLockFile>
+#include <QPalette>
+#include <QIcon>
 
 #define RECENT_FILES        10
 #define RECENT_SEARCHES     20
@@ -266,3 +268,13 @@ void QTextPadSettings::addRecentSearchReplacement(const QString &text)
         replacements.removeLast();
     m_settings.setValue(QStringLiteral("Search/RecentReplace"), replacements);
 }
+
+QIcon QTextPadSettings::staticIcon(const QString &iconName, const QPalette &palette)
+{
+    const bool darkTheme = palette.color(QPalette::Window).lightness() < 128;
+    qDebug("Lightness = %d", palette.color(QPalette::Window).lightness());
+    const QString iconPattern = darkTheme
+            ? QStringLiteral(":/icons/qtextpad-dark/16x16/actions/%1.png")
+            : QStringLiteral(":/icons/qtextpad/16x16/actions/%1.png");
+    return QIcon(iconPattern.arg(iconName));
+}

src/appsettings.h

@@ -109,12 +109,13 @@ class QTextPadSettings
     SIMPLE_SETTING(bool, "Search/Escapes", searchEscapes, setSearchEscapes, false)
     SIMPLE_SETTING(bool, "Search/Wrap", searchWrap, setSearchWrap, true)
 
+    static QIcon staticIcon(const QString &iconName, const QPalette &palette);
+
 private:
     QSettings m_settings;
 };
 
 /* Helper for loading theme icons */
 #define ICON(name)      QIcon::fromTheme(QStringLiteral(name))
-#define ICON_S16(name)  QIcon(QStringLiteral(":/icons/qtextpad/16x16/actions/" name ".png"))
 
 #endif // QTEXTPAD_APPSETTINGS_H

src/icons/qtextpad-dark/index.theme

@@ -0,0 +1,15 @@
+[Icon Theme]
+Name=qtextpad-dark
+Comment=Default qtextpad dark theme, based on Breeze-dark
+
+Directories=16x16/actions,22x22/actions
+
+[16x16/actions]
+Size=16
+Context=Actions
+Type=Fixed
+
+[22x22/actions]
+Size=22
+Context=Actions
+Type=Fixed

src/qtextpad.qrc

@@ -8,10 +8,8 @@
         <file>icons/qtextpad-64.png</file>
         <file>icons/qtextpad-128.png</file>
 
-        <!-- Used by the filter widgets -->
-        <file>icons/search-filter.png</file>
-
-        <!-- Oxygen icons for Win/Mac and Unixes that don't have a usable theme -->
+        <!-- Fallback icon themes for Win/Mac and Unixes that don't have a usable
+             theme, plus icons for widgets that don't use themes -->
         <file>icons/qtextpad/index.theme</file>
         <file>icons/qtextpad/16x16/actions/application-menu.png</file>
         <file>icons/qtextpad/16x16/actions/document-new.png</file>
@@ -33,6 +31,7 @@
         <file>icons/qtextpad/16x16/actions/go-jump.png</file>
         <file>icons/qtextpad/16x16/actions/go-up.png</file>
         <file>icons/qtextpad/16x16/actions/help-about.png</file>
+        <file>icons/qtextpad/16x16/actions/search-filter.png</file>
         <file>icons/qtextpad/16x16/actions/view-fullscreen.png</file>
         <file>icons/qtextpad/16x16/actions/view-refresh.png</file>
         <file>icons/qtextpad/16x16/actions/view-restore.png</file>
@@ -64,5 +63,11 @@
         <file>icons/qtextpad/22x22/actions/zoom-in.png</file>
         <file>icons/qtextpad/22x22/actions/zoom-original.png</file>
         <file>icons/qtextpad/22x22/actions/zoom-out.png</file>
+
+        <file>icons/qtextpad-dark/index.theme</file>
+        <file>icons/qtextpad-dark/16x16/actions/application-menu.png</file>
+        <file>icons/qtextpad-dark/16x16/actions/go-down.png</file>
+        <file>icons/qtextpad-dark/16x16/actions/go-up.png</file>
+        <file>icons/qtextpad-dark/16x16/actions/search-filter.png</file>
     </qresource>
 </RCC>

src/searchdialog.cpp

@@ -50,9 +50,9 @@ SearchWidget::SearchWidget(QTextPadWindow *parent)
     : QWidget(parent), m_editor(parent->editor())
 {
     auto tbMenu = new QToolButton(this);
+    const QPalette &pal = palette();
     tbMenu->setAutoRaise(true);
-    tbMenu->setIconSize(QSize(16, 16));
-    tbMenu->setIcon(ICON_S16("application-menu"));
+    tbMenu->setIcon(QTextPadSettings::staticIcon(QStringLiteral("application-menu"), pal));
     tbMenu->setToolTip(tr("Search Settings"));
     tbMenu->setStyleSheet(QStringLiteral("QToolButton::menu-indicator { image: none; }"));
 
@@ -82,14 +82,12 @@ SearchWidget::SearchWidget(QTextPadWindow *parent)
 
     auto tbNext = new QToolButton(this);
     tbNext->setAutoRaise(true);
-    tbNext->setIconSize(QSize(16, 16));
-    tbNext->setIcon(ICON_S16("go-down"));
+    tbNext->setIcon(QTextPadSettings::staticIcon(QStringLiteral("go-down"), pal));
     tbNext->setToolTip(tr("Find Next"));
 
     auto tbPrev = new QToolButton(this);
     tbPrev->setAutoRaise(true);
-    tbPrev->setIconSize(QSize(16, 16));
-    tbPrev->setIcon(ICON_S16("go-up"));
+    tbPrev->setIcon(QTextPadSettings::staticIcon(QStringLiteral("go-up"), pal));
     tbPrev->setToolTip(tr("Find Previous"));
 
     auto layout = new QHBoxLayout(this);

src/settingspopup.cpp

@@ -27,13 +27,14 @@
 
 #include <KSyntaxHighlighting/Repository>
 
+#include "appsettings.h"
 #include "syntaxtextedit.h"
 #include "charsets.h"
 
 TreeFilterEdit::TreeFilterEdit(QWidget *parent)
     : QLineEdit(parent)
 {
-    m_searchIcon = QIcon(QStringLiteral(":/icons/search-filter.png"));
+    m_searchIcon = QTextPadSettings::staticIcon(QStringLiteral("search-filter"), palette());
     setClearButtonEnabled(true);
     resizeEvent(Q_NULLPTR);
 }