Files
qelectrotech-source-mirror/sources/utils/qetutils.cpp
T
Dieter Mayer 5da1fe5fc8 Write font descriptions in the stable Qt 5 10/11-field format
QFont::toString() is not stable across Qt versions: Qt 6.11 switched to
a 19-field format carrying OpenType weights, which QFont::fromString()
of Qt 5.x and Qt <= 6.10 rejects, leaving a broken font. Projects saved
by a Qt 6.11+ build were therefore unreadable by older builds.

Add QETUtils::fontToString() composing the legacy 10/11-field
description (weight mapped back to the legacy scale with the same
closest-match table Qt uses when parsing) and use it at every site that
stores a font description in a project, element, table config or
settings file. Every Qt version from 5.15 through 6.12-beta parses this
form correctly, so files stay readable by every QET build in
circulation.

See issue #553.
2026-07-30 21:45:36 +02:00

209 lines
6.2 KiB
C++

/*
Copyright 2006-2026 The QElectroTech Team
This file is part of QElectroTech.
QElectroTech is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 2 of the License, or
(at your option) any later version.
QElectroTech is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with QElectroTech. If not, see <http://www.gnu.org/licenses/>.
*/
#include "qetutils.h"
#include <QString>
#include <QStringList>
#include <QGraphicsView>
#include "../qetapp.h"
#include "../qetdiagrameditor.h"
/**
@brief QETUtils::marginsToString
@param margins
@return QString str "left;top;right;bottom"
*/
QString QETUtils::marginsToString(const QMargins &margins)
{
QString str;
str += QString::number(margins.left());
str += ";";
str += QString::number(margins.top());
str += ";";
str += QString::number(margins.right());
str += ";";
str += QString::number(margins.bottom());
return str;
}
/**
@brief QETUtils::marginsFromString
@param string
@return QMargins margins
*/
QMargins QETUtils::marginsFromString(const QString &string)
{
QMargins margins;
auto split = string.split(";");
if (split.size() != 4)
return margins;
margins.setLeft (split.at(0).toInt());
margins.setTop (split.at(1).toInt());
margins.setRight (split.at(2).toInt());
margins.setBottom(split.at(3).toInt());
return margins;
}
/**
* @brief QETUtils::graphicsHandlerSize
* @param item
* @return Return the handler size to use in the QGraphicsScene of @a item.
* If size can't be found, return 10 by default.
*/
qreal QETUtils::graphicsHandlerSize(QGraphicsItem *item)
{
if (const auto scene_ = item->scene())
{
if (!scene_->views().isEmpty())
{
if (const auto editor_ = QETApp::instance()->diagramEditorAncestorOf(scene_->views().at(0)))
{
const auto variant_ = editor_->property("graphics_handler_size");
//If variant_ can't be converted to qreal, the returned qreal is 0.0
//it's sufficient for us to check if value is set or not.
if (const auto value_ = variant_.toReal())
return value_;
}
}
}
//Default value
return 10;
}
/**
* @brief QETUtils::sortBeginIntString
* Sort the string @a str_a and @a str_b and take in
* count if string begin with an int to sort it
* as int and not as string in this case.
* For example if we have to sort the string :
* "3str", 10str", "100str", "2str", "20str".
* The default behavior when sorting QString with the comparison operator will be:
* "10str" "100str" "2str", "20str", "3str"
* When sorting with this function, the result will be :
* "10str", "2str", "3str", "20str", "100str"
* @param str_a
* @param str_b
* @return
*/
bool QETUtils::sortBeginIntString(const QString &str_a, const QString &str_b)
{
const QRegularExpression rx(QStringLiteral("^\\d+"));
int int_a =-1;
int int_b =-1;
auto match_a = rx.match(str_a);
if (match_a.hasMatch()) {
int_a = match_a.captured(0).toInt();
}
auto match_b = rx.match(str_b);
if (match_b.hasMatch()) {
int_b = match_b.captured(0).toInt();
}
//Sort as numbers if both string
//start at least by a digit and
//the number of each string are different.
//Else sort as string
if (int_a >= 0 &&
int_b >= 0 &&
int_a != int_b) {
return int_a<int_b;
}
else {
return str_a<str_b;
}
}
/**
* @brief QETUtils::pixelSizedFont
* Set the font size to pixelSize instead of pointSize (if needed).
* The font used to draw diagram must be pixel sized instead of point sized (default by Qt)
* then no matter the screen dpi used, the text in diagram keep the same size.
* For more information see @link https://qelectrotech.org/forum/viewtopic.php?pid=6267#p6267 @endlink
* @param font
*/
void QETUtils::pixelSizedFont(QFont &font)
{
if (font.pixelSize() > -1) {
return;
}
auto px = font.pointSizeF()/72 * QFontMetrics{font}.fontDpi();
font.setPixelSize(qRound(px));
}
/**
* @brief QETUtils::fontToString
* Serialize a font to the 10/11 field description format written by Qt 5,
* to be used instead of QFont::toString() everywhere a font description is
* stored in a project, element or settings file.
* The format of QFont::toString() is not stable across Qt versions : Qt 6.11
* switched to a 19 field format carrying OpenType weights, which
* QFont::fromString() of Qt 5.x and Qt <= 6.10 rejects, leaving a broken font.
* The 10/11 field form is parsed correctly by every Qt version (they convert
* the legacy weight scale as needed), so composing it ourselves keeps files
* readable by every QET build in circulation.
* See @link https://github.com/qelectrotech/qelectrotech-source-mirror/issues/553 @endlink
* @param font
* @return the font description string
*/
QString QETUtils::fontToString(const QFont &font)
{
#if QT_VERSION < QT_VERSION_CHECK(6, 0, 0)
return font.toString();
#else
//Legacy (Qt 5) weight <- OpenType weight, closest match,
//same table Qt uses when parsing a 10/11 field string.
static const int weight_map[9][2] = {
{0, 100}, {12, 200}, {25, 300}, {50, 400}, {57, 500},
{63, 600}, {75, 700}, {81, 800}, {87, 900}
};
const int weight = font.weight();
int legacy_weight = weight_map[0][0];
int closest_diff = qAbs(weight - weight_map[0][1]);
for (int i = 1 ; i < 9 ; ++i)
{
const int diff = qAbs(weight - weight_map[i][1]);
if (diff < closest_diff) {
closest_diff = diff;
legacy_weight = weight_map[i][0];
}
}
const QChar comma(QLatin1Char(','));
QString description = font.family() + comma +
QString::number(font.pointSizeF()) + comma +
QString::number(font.pixelSize()) + comma +
QString::number(int(font.styleHint())) + comma +
QString::number(legacy_weight) + comma +
QString::number(int(font.style())) + comma +
QString::number(int(font.underline())) + comma +
QString::number(int(font.strikeOut())) + comma +
QString::number(int(font.fixedPitch())) + comma +
QString::number(0);
if (!font.styleName().isEmpty()) {
description += QChar(',') + font.styleName();
}
return description;
#endif
}