1 files changed, 140 insertions, 0 deletions
diff --git a/src/pattern-manipulation.cpp b/src/pattern-manipulation.cpp
new file mode 100644
index 0000000..910a449
--- /dev/null
+++ b/src/pattern-manipulation.cpp
@@ -0,0 +1,140 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <glibmm/fileutils.h>
+#include <glibmm/i18n.h>
+#include "pattern-manipulation.h"
+#include "document.h"
+#include "color.h"
+#include "helper/stock-items.h"
+#include "object/sp-pattern.h"
+#include "io/resource.h"
+#include "xml/repr.h"
+
+
+std::vector<std::shared_ptr<SPDocument>> sp_get_stock_patterns() {
+    auto patterns = sp_get_paint_documents([](SPDocument* doc){
+        return !sp_get_pattern_list(doc).empty();
+    });
+    if (patterns.empty()) {
+        g_warning("No stock patterns!");
+    }
+    return patterns;
+}
+
+std::vector<SPPattern*> sp_get_pattern_list(SPDocument* source) {
+    std::vector<SPPattern*> list;
+    if (!source) return list;
+
+    std::vector<SPObject*> patterns = source->getResourceList("pattern");
+    for (auto pattern : patterns) {
+        auto p = cast<SPPattern>(pattern);
+        if (p && p == p->rootPattern() && p->hasChildren()) { // only if this is a vali root pattern
+            list.push_back(cast<SPPattern>(pattern));
+        }
+    }
+
+    return list;
+}
+
+void sp_pattern_set_color(SPPattern* pattern, unsigned int color) {
+    if (!pattern) return;
+
+    SPColor c(color);
+    SPCSSAttr* css = sp_repr_css_attr_new();
+    sp_repr_css_set_property(css, "fill", c.toString().c_str());
+    pattern->changeCSS(css, "style");
+    sp_repr_css_attr_unref(css);
+}
+
+void sp_pattern_set_transform(SPPattern* pattern, const Geom::Affine& transform) {
+    if (!pattern) return;
+
+    // for now, this is that simple
+    pattern->transform_multiply(transform, true);
+}
+
+void sp_pattern_set_offset(SPPattern* pattern, const Geom::Point& offset) {
+    if (!pattern) return;
+
+    // TODO: verify
+    pattern->setAttributeDouble("x", offset.x());
+    pattern->setAttributeDouble("y", offset.y());
+}
+
+void sp_pattern_set_uniform_scale(SPPattern* pattern, bool uniform) {
+    if (!pattern) return;
+
+    //TODO: make smarter to keep existing value when possible
+    pattern->setAttribute("preserveAspectRatio", uniform ? "xMidYMid" : "none");
+}
+
+void sp_pattern_set_gap(SPPattern* link_pattern, Geom::Scale gap_percent) {
+    if (!link_pattern) return;
+    auto root = link_pattern->rootPattern();
+    if (!root || root == link_pattern) {
+        g_assert(false && "Setting pattern gap requires link and root patterns objects");
+        return;
+    }
+
+    auto set_gap = [=](double size, double percent, const char* attr) {
+        if (percent == 0.0 || size <= 0.0) {
+            // no gap
+            link_pattern->removeAttribute(attr);
+        }
+        else if (percent > 0.0) {
+            // positive gap
+            link_pattern->setAttributeDouble(attr, size + size * percent / 100.0);
+        }
+        else if (percent < 0.0 && percent > -100.0) {
+            // negative gap - overlap
+            percent = -percent;
+            link_pattern->setAttributeDouble(attr, size - size * percent / 100.0);
+        }
+    };
+
+    set_gap(root->width(), gap_percent[Geom::X], "width");
+    set_gap(root->height(), gap_percent[Geom::Y], "height");
+}
+
+Geom::Scale sp_pattern_get_gap(SPPattern* link_pattern) {
+    Geom::Scale gap(0, 0);
+
+    if (!link_pattern) return gap;
+    auto root = link_pattern->rootPattern();
+    if (!root || root == link_pattern) {
+        g_assert(false && "Reading pattern gap requires link and root patterns objects");
+        return gap;
+    }
+
+    auto get_gap = [=](double root_size, double link_size) {
+        if (root_size > 0.0 && link_size > 0.0) {
+            if (link_size > root_size) {
+                return (link_size - root_size) / root_size;
+            }
+            else if (link_size < root_size) {
+                return -link_size / root_size;
+            }
+        }
+        return 0.0;
+    };
+
+    return Geom::Scale(
+        get_gap(root->width(),  link_pattern->width())  * 100.0,
+        get_gap(root->height(), link_pattern->height()) * 100.0
+    );
+}
+
+
+std::string sp_get_pattern_label(SPPattern* pattern) {
+    if (!pattern) return std::string();
+
+    Inkscape::XML::Node* repr = pattern->getRepr();
+    if (auto label = pattern->getAttribute("inkscape:label")) {
+        if (*label) {
+            return std::string(gettext(label));
+        }
+    }
+    const char* stock_id = _(repr->attribute("inkscape:stockid"));
+    const char* pat_id = stock_id ? stock_id : _(repr->attribute("id"));
+    return std::string(pat_id ? pat_id : "");
+}