9-patch export plugin for Sketch

This plugin crops upscaled 9-patch PNG assets when exported from Sketch,
to ensure that 9-patch borders remain 1px wide when upscaled.

Change-Id: Iad46d75f37b76eecf64ac32fa38d2b9e9db8b34d
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

3 files changed, 44 insertions, 1 deletions

diff --git a/src/imports/controls/imagine/design/9-patch-export.sketchplugin/Contents/Sketch/9-patch-export.js b/src/imports/controls/imagine/design/9-patch-export.sketchplugin/Contents/Sketch/9-patch-export.js
new file mode 100644
index 00000000..a7f9a459
--- /dev/null
+++ b/src/imports/controls/imagine/design/9-patch-export.sketchplugin/Contents/Sketch/9-patch-export.js
@@ -0,0 +1,24 @@
+// 9-patch export
+//
+// This plugin crops upscaled 9-patch PNG assets when exported from Sketch,
+// to ensure that 9-patch borders remain 1px wide when upscaled.
+//
+function onExportSlices(context) {
+    var exports = context.actionContext.exports;
+    for (var i = 0; i < exports.count(); ++i) {
+        var name = exports[i].request.name();
+        var scale = exports[i].request.scale();
+        if (scale > 1 && name.endsWith(".9"))
+            cropAsset(exports[i].path, scale - 1);
+    }
+}
+
+function cropAsset(path, inset) {
+    var url = NSURL.fileURLWithPath(path);
+    var img = CIImage.imageWithContentsOfURL(url);
+    var rect = NSInsetRect(img.extent(), inset, inset);
+    var cropped = img.imageByCroppingToRect(rect);
+    var rep = NSBitmapImageRep.alloc().initWithCIImage(cropped);
+    var data = rep.PNGRepresentationWithInterlaced(false);
+    data.writeToFile(path);
+}
diff --git a/src/imports/controls/imagine/design/9-patch-export.sketchplugin/Contents/Sketch/manifest.json b/src/imports/controls/imagine/design/9-patch-export.sketchplugin/Contents/Sketch/manifest.json
new file mode 100644
index 00000000..40807aa3
--- /dev/null
+++ b/src/imports/controls/imagine/design/9-patch-export.sketchplugin/Contents/Sketch/manifest.json
@@ -0,0 +1,19 @@
+{
+    "name" : "9-patch export",
+    "description" : "Crops upscaled 9-patch PNG assets when exported from Sketch.",
+    "version" : "0.1",
+    "identifier" : "org.qt-project.sketch.9-patch-export",
+    "author" : "The Qt Project",
+    "commands" : [
+        {
+            "name" : "9-patch export",
+            "identifier" : "9-patch-export",
+            "script" : "9-patch-export.js",
+            "handlers" : {
+                "actions" : {
+                    "ExportSlices": "onExportSlices",
+                },
+            },
+        },
+    ],
+}
diff --git a/tests/auto/sanity/tst_sanity.cpp b/tests/auto/sanity/tst_sanity.cpp
index 2c67e86a..96c8eb38 100644
--- a/tests/auto/sanity/tst_sanity.cpp
+++ b/tests/auto/sanity/tst_sanity.cpp
@@ -139,7 +139,7 @@ private:
 void tst_Sanity::initTestCase()
 {
     QDirIterator it(QQC2_IMPORT_PATH, QStringList() << "*.qml" << "*.js", QDir::Files, QDirIterator::Subdirectories);
-    const QStringList excludeDirs = QStringList() << QStringLiteral("snippets") << QStringLiteral("designer");
+    const QStringList excludeDirs = QStringList() << QStringLiteral("snippets") << QStringLiteral("designer") << QStringLiteral("Sketch");
     while (it.hasNext()) {
         it.next();
         QFileInfo info = it.fileInfo();