DM: add --writePath

dm/DMWriteTask.cpp

Index: dm/DMWriteTask.cpp
diff --git a/dm/DMWriteTask.cpp b/dm/DMWriteTask.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..21a9b55bc33037d5aea527a9747aafc6d226a622
--- /dev/null
+++ b/dm/DMWriteTask.cpp
@@ -0,0 +1,47 @@
+#include "DMWriteTask.h"
+
+#include "DMUtil.h"
+#include "SkCommandLineFlags.h"
+#include "SkImageEncoder.h"
+
+#include <string.h>
+
+DEFINE_string2(writePath, w, "", "If set, write GMs here as .pngs.");
+
+namespace DM {
+
+WriteTask::WriteTask(const Task& parent, SkBitmap bitmap)
+    : Task(parent)
+    , fBitmap(bitmap) {
+    // Split parent's name <gmName>_<config> into gmName and config.
+    const char* parentName = parent.name().c_str();
+    const char* fromLastUnderscore = strrchr(parentName, '_');
+    const ptrdiff_t gmNameLength = fromLastUnderscore - parentName;
+
+    fConfig.set(fromLastUnderscore+1);
+    fGmName.set(parentName, gmNameLength);
+}
+
+void WriteTask::draw() {
+    const char* root = FLAGS_writePath[0];
+    const SkString dir = SkOSPath::SkPathJoin(root, fConfig.c_str());
+    if (!sk_mkdir(root) ||
+        !sk_mkdir(dir.c_str())  ||
+        !SkImageEncoder::EncodeFile(png(SkOSPath::SkPathJoin(dir.c_str(), fGmName.c_str())).c_str(),
+                                    fBitmap,
+                                    SkImageEncoder::kPNG_Type,
+                                    100/*quality*/))
+    {
+        this->fail();
+    }
+}
+
+SkString WriteTask::name() const {
+    return SkStringPrintf("writing %s/%s.png", fConfig.c_str(), fGmName.c_str());
+}
+
+bool WriteTask::shouldSkip() const {
+    return FLAGS_writePath.isEmpty();
+}
+
+}  // namespace DM