Support compiling app icon sets. (#94)

* Pass through info and dependency info options to asset compile output.

Fixes writing out additional info plist and dependency info.

* Add initial implementation of compiling app icons.

Supports copying the images and writing the icon metadata to info
plist additions. Current implementation has two limitations:

 - All idioms are copied for all target platforms. For example, watch
   images are copied for asset compilation targeting a phone.
 - The size of images is not verified against the specified dimensions.

Libraries/acdriver/Sources/Compile/AppIconSet.cpp

@@ -10,6 +10,10 @@
 #include <acdriver/Compile/AppIconSet.h>
 #include <acdriver/CompileOutput.h>
 #include <acdriver/Result.h>
+#include <plist/Array.h>
+#include <plist/Boolean.h>
+#include <plist/Dictionary.h>
+#include <plist/String.h>
 #include <libutil/Filesystem.h>
 
 using acdriver::Compile::AppIconSet;
@@ -17,6 +21,50 @@ using acdriver::CompileOutput;
 using acdriver::Result;
 using libutil::Filesystem;
 
+static plist::Dictionary *
+IconsDictionary(plist::Dictionary *info, std::string const &key)
+{
+    if (auto existing = info->value<plist::Dictionary>(key)) {
+        return existing;
+    } else {
+        auto icons = plist::Dictionary::New();
+        info->set(key, std::move(icons));
+        return info->value<plist::Dictionary>(key);
+    }
+}
+
+static std::string
+IdiomSuffix(xcassets::Slot::Idiom idiom)
+{
+    switch (idiom) {
+        case xcassets::Slot::Idiom::Universal:
+            return std::string();
+        case xcassets::Slot::Idiom::Phone:
+            return std::string();
+        case xcassets::Slot::Idiom::Pad:
+            return "~ipad";
+        case xcassets::Slot::Idiom::Desktop:
+            // TODO: no idiom suffix for desktop
+            return std::string();
+        case xcassets::Slot::Idiom::TV:
+            return "~tv";
+        case xcassets::Slot::Idiom::Watch:
+            return "~watch";
+        case xcassets::Slot::Idiom::Car:
+            return "~car";
+    }
+
+    abort();
+}
+
+struct IdiomHash
+{
+    std::size_t operator()(xcassets::Slot::Idiom idiom) const
+    {
+        return static_cast<std::size_t>(idiom);
+    }
+};
+
 bool AppIconSet::
 Compile(
     std::shared_ptr<xcassets::Asset::AppIconSet> const &appIconSet,
@@ -24,12 +72,85 @@ Compile(
     CompileOutput *compileOutput,
     Result *result)
 {
-    result->document(
-        Result::Severity::Warning,
-        appIconSet->path(),
-        { CompileOutput::AssetReference(appIconSet) },
-        "Not Implemented",
-        "app icon set not yet supported");
+    /*
+     * Copy the app icon images into the output.
+     */
+    auto files = std::unordered_map<xcassets::Slot::Idiom, std::vector<std::string>, IdiomHash>();
+    if (appIconSet->images()) {
+        for (xcassets::Asset::AppIconSet::Image const &image : *appIconSet->images()) {
+            /*
+             * Verify the image has the required information.
+             */
+            if (image.unassigned() || !image.fileName() || !image.imageSize() || !image.scale()) {
+                result->document(
+                    Result::Severity::Warning,
+                    appIconSet->path(),
+                    { CompileOutput::AssetReference(appIconSet) },
+                    "Ambiguous Content",
+                    "an icon in \"" + appIconSet->name().name() + "\" is unassigned");
+                continue;
+            }
 
-    return false;
+            /*
+             * Determine information about the icon image.
+             */
+            xcassets::Slot::ImageSize const &size = *image.imageSize();
+            // TODO: verify the dimensions of the image are correct
+            std::string sizeSuffix = xcassets::Slot::ImageSize::String(size);
+
+            xcassets::Slot::Scale const &scale = *image.scale();
+            std::string scaleSuffix = std::string();
+            if (scale.value() != 1.0) {
+                scaleSuffix = "@" + xcassets::Slot::Scale::String(scale);
+            }
+
+            xcassets::Slot::Idiom idiom = image.idiom().value_or(xcassets::Slot::Idiom::Universal);
+            // TODO: skip images with idioms inappropriate for target platform
+            std::string idiomSuffix = IdiomSuffix(idiom);
+
+            /*
+             * Copy the icon image into the output.
+             */
+            std::string source = appIconSet->path() + "/" + *image.fileName();
+            std::string destination = compileOutput->root() + "/" + appIconSet->name().name() + sizeSuffix + scaleSuffix + idiomSuffix + ".png";
+            compileOutput->copies().push_back({ source, destination });
+
+            /*
+             * Add the file to the output info.
+             */
+            std::string name = appIconSet->name().name() + sizeSuffix;
+            files[idiom].push_back(name);
+        }
+    }
+
+    /*
+     * Build up the info about the icons.
+     */
+    for (auto const &pair : files) {
+        /*
+         * Record details about the icon itself.
+         */
+        auto primary = plist::Dictionary::New();
+
+        /* List the files for the icon. */
+        auto files = plist::Array::New();
+        for (std::string const &file : pair.second) {
+            files->append(plist::String::New(file));
+        }
+        primary->set("CFBundleIconFiles", std::move(files));
+
+        /* Record if the icon is pre-rendered. */
+        if (appIconSet->preRendered()) {
+            primary->set("UIPrerenderedIcon", plist::Boolean::New(true));
+        }
+
+        /*
+         * Store the icon in the additional info.
+         */
+        std::string idiomSuffix = IdiomSuffix(pair.first);
+        plist::Dictionary *icons = IconsDictionary(compileOutput->additionalInfo(), "CFBundleIcons" + idiomSuffix);
+        icons->set("CFBundlePrimaryIcon", std::move(primary));
+    }
+
+    return true;
 }

Libraries/acdriver/Sources/CompileAction.cpp

@@ -302,7 +302,9 @@ run(Filesystem *filesystem, Options const &options, Output *output, Result *resu
     /*
      * Write out the output.
      */
-    if (!compileOutput.write(filesystem, ext::nullopt, ext::nullopt, result)) {
+    ext::optional<std::string> partialInfoPlist = (!options.outputPartialInfoPlist().empty() ? ext::optional<std::string>(options.outputPartialInfoPlist()) : ext::nullopt);
+    ext::optional<std::string> dependencyInfo = (!options.exportDependencyInfo().empty() ? ext::optional<std::string>(options.exportDependencyInfo()) : ext::nullopt);
+    if (!compileOutput.write(filesystem, partialInfoPlist, dependencyInfo, result)) {
         /* Error already reported. */
     }
 }