OmaPhoto 1.0.0: the Linux port of Compositor

A layered image editor for Linux and Omarchy, ported from Compositor
(github.com/robbietilton/Compositor), whose Swift source is its
specification. It reads and writes Compositor's .comp projects.

Packages for Ubuntu, Fedora and Arch come from the release workflow;
scripts/install/ holds one install script per distribution family,
and flake.nix serves NixOS.

Co-Authored-By: Claude <noreply@anthropic.com>

src/UI/NewCanvasSheet.cpp

@@ -0,0 +1,134 @@
+#include "UI/NewCanvasSheet.h"
+#include <QApplication>
+#include <QBuffer>
+#include <QClipboard>
+#include <QGridLayout>
+#include <QImageReader>
+#include <QShortcut>
+#include <QVBoxLayout>
+
+namespace {
+QLabel *text(const QString &words, int pixels, QFont::Weight weight, QPalette::ColorRole role, QWidget *parent)
+{
+    auto *label = new QLabel(words, parent);
+    QFont font = label->font();
+    font.setPixelSize(pixels);
+    font.setWeight(weight);
+    label->setFont(font);
+    label->setForegroundRole(role);
+    return label;
+}
+}
+
+NewCanvasSheet::NewCanvasSheet(EditorSession &session, std::function<void(int, int)> onCreate, std::function<void()> onOpen, QWidget *parent)
+    : QWidget(parent), m_session(session), m_onCreate(std::move(onCreate)), m_width(new QLineEdit(QStringLiteral("1920"), this)),
+      m_height(new QLineEdit(QStringLiteral("1080"), this)), m_note(text(QString(), 12, QFont::Normal, QPalette::PlaceholderText, this)),
+      m_create(new QPushButton(QStringLiteral("Create canvas"), this))
+{
+    // Swift's fields stretch the sheet to its full 500 points.
+    setFixedWidth(500);
+    m_width->setObjectName(QStringLiteral("widthInput"));
+    m_height->setObjectName(QStringLiteral("heightInput"));
+    m_note->setObjectName(QStringLiteral("canvasNote"));
+    m_create->setObjectName(QStringLiteral("createCanvas"));
+    m_create->setDefault(true);
+    auto *open = new QPushButton(QStringLiteral("Open project"), this);
+    open->setObjectName(QStringLiteral("openProject"));
+    auto *import = new QPushButton(QStringLiteral("Import image"), this);
+    import->setObjectName(QStringLiteral("importImage"));
+
+    auto *fields = new QGridLayout;
+    fields->setHorizontalSpacing(16);
+    fields->setVerticalSpacing(8);
+    fields->addWidget(text(QStringLiteral("Width"), 12, QFont::Medium, QPalette::WindowText, this), 0, 0);
+    fields->addWidget(text(QStringLiteral("Height"), 12, QFont::Medium, QPalette::WindowText, this), 0, 3);
+    fields->addWidget(m_width, 1, 0);
+    fields->addWidget(text(QStringLiteral("px"), 12, QFont::Normal, QPalette::PlaceholderText, this), 1, 1);
+    fields->addWidget(text(QStringLiteral("×"), 14, QFont::Normal, QPalette::PlaceholderText, this), 1, 2);
+    fields->addWidget(m_height, 1, 3);
+    fields->addWidget(text(QStringLiteral("px"), 12, QFont::Normal, QPalette::PlaceholderText, this), 1, 4);
+
+    auto *buttons = new QHBoxLayout;
+    buttons->setSpacing(10);
+    buttons->addWidget(open);
+    buttons->addWidget(import);
+    buttons->addStretch(1);
+    buttons->addWidget(m_create);
+
+    auto *column = new QVBoxLayout(this);
+    column->setContentsMargins(28, 28, 28, 28);
+    column->setSpacing(24);
+    auto *heading = new QVBoxLayout;
+    heading->setSpacing(6);
+    heading->addWidget(text(QStringLiteral("New canvas"), 17, QFont::DemiBold, QPalette::WindowText, this));
+    heading->addWidget(text(QStringLiteral("A blank space for your next composition."), 13, QFont::Normal, QPalette::PlaceholderText, this));
+    column->addLayout(heading);
+    column->addLayout(fields);
+    column->addWidget(m_note);
+    column->addLayout(buttons);
+
+    connect(m_width, &QLineEdit::textChanged, this, &NewCanvasSheet::validate);
+    connect(m_height, &QLineEdit::textChanged, this, &NewCanvasSheet::validate);
+    // Return anywhere on the sheet is the default action.
+    for (const Qt::Key key : {Qt::Key_Return, Qt::Key_Enter})
+        new QShortcut(QKeySequence(key), this, this, &NewCanvasSheet::create, Qt::WidgetWithChildrenShortcut);
+    connect(m_create, &QPushButton::clicked, this, &NewCanvasSheet::create);
+    connect(open, &QPushButton::clicked, this, [onOpen = std::move(onOpen)] { onOpen(); });
+    connect(import, &QPushButton::clicked, this, [this] { m_session.setShowsImporter(true); });
+    connect(&m_session, &EditorSession::changed, this, &NewCanvasSheet::synchronize);
+    synchronize();
+    validate();
+}
+
+void NewCanvasSheet::synchronize()
+{
+    setEnabled(!m_session.isImporting() && !m_session.showsBusy());
+}
+
+void NewCanvasSheet::validate()
+{
+    const bool valid = CanvasDocument::validDimension(m_width->text()) && CanvasDocument::validDimension(m_height->text());
+    m_note->setText(valid ? QStringLiteral("Transparent canvas · sRGB") : QStringLiteral("Enter whole numbers from 1 to 30,000 pixels."));
+    // The palette's bright text is the theme's warning colour.
+    m_note->setForegroundRole(valid ? QPalette::PlaceholderText : QPalette::BrightText);
+    m_create->setEnabled(valid);
+}
+
+void NewCanvasSheet::create()
+{
+    const std::optional<int> width = CanvasDocument::validDimension(m_width->text()), height = CanvasDocument::validDimension(m_height->text());
+    if (width && height)
+        m_onCreate(*width, *height);
+}
+
+void NewCanvasSheet::showEvent(QShowEvent *event)
+{
+    QWidget::showEvent(event);
+    if (!m_suggestedClipboardSize) {
+        m_suggestedClipboardSize = true;
+        if (m_session.skipsInitialClipboardCanvasSize) {
+            m_session.skipsInitialClipboardCanvasSize = false;
+        } else if (const std::optional<QSize> size = clipboardDimensions(QApplication::clipboard()->mimeData())) {
+            m_width->setText(QString::number(size->width()));
+            m_height->setText(QString::number(size->height()));
+        }
+    }
+    m_width->setFocus();
+}
+
+std::optional<QSize> NewCanvasSheet::clipboardDimensions(const QMimeData *clipboard)
+{
+    for (const QString &type : {QStringLiteral("image/png"), QStringLiteral("image/tiff")}) {
+        QByteArray data = clipboard ? clipboard->data(type) : QByteArray();
+        QBuffer buffer(&data);
+        QImageReader reader(&buffer);
+        QSize size = reader.size();
+        // Stored on its side, a picture swaps its sides.
+        if (reader.transformation() & QImageIOHandler::TransformationRotate90)
+            size.transpose();
+        // In range on one side alone is no canvas.
+        if (CanvasDocument::validDimension(QString::number(size.width())) && CanvasDocument::validDimension(QString::number(size.height())))
+            return size;
+    }
+    return std::nullopt;
+}