Initial commit of our new Android app to demo Skia.

tools/viewer/sk_app/android/surface_glue_android.cpp

+/*
+* Copyright 2016 Google Inc.
+*
+* Use of this source code is governed by a BSD-style license that can be
+* found in the LICENSE file.
+*/
+
+#include "surface_glue_android.h"
+
+#include <jni.h>
+#include <pthread.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include <android/looper.h>
+#include <android/native_window_jni.h>
+
+#include "../Application.h"
+#include "SkTypes.h"
+#include "SkUtils.h"
+#include "Window_android.h"
+
+namespace sk_app {
+
+static const int LOOPER_ID_MESSAGEPIPE = 1;
+
+void* pthread_main(void* arg);
+
+SkiaAndroidApp::SkiaAndroidApp() {
+    fNativeWindow = nullptr;
+    pthread_create(&fThread, nullptr, pthread_main, this);
+}
+
+SkiaAndroidApp::~SkiaAndroidApp() {
+    if (fWindow) {
+        fWindow->detach();
+    }
+    if (fNativeWindow) {
+        ANativeWindow_release(fNativeWindow);
+        fNativeWindow = nullptr;
+    }
+    if (fApp) {
+        delete fApp;
+    }
+}
+
+void SkiaAndroidApp::paintIfNeeded() {
+    if (fNativeWindow && fWindow) {
+        fWindow->onPaint();
+    }
+}
+
+void SkiaAndroidApp::postMessage(const Message& message) {
+    auto writeSize = write(fPipes[1], &message, sizeof(message));
+    SkASSERT(writeSize == sizeof(message));
+}
+
+void SkiaAndroidApp::readMessage(Message* message) {
+    auto readSize = read(fPipes[0], message, sizeof(Message));
+    SkASSERT(readSize == sizeof(Message));
+}
+
+static int message_callback(int fd, int events, void* data) {
+    auto skiaAndroidApp = (SkiaAndroidApp*)data;
+    Message message;
+    skiaAndroidApp->readMessage(&message);
+    SkDebugf("message_callback %d", message.fType);
+    SkASSERT(message.fType != kUndefined);
+
+    switch (message.fType) {
+        case kDestroyApp: {
+            delete skiaAndroidApp;
+            pthread_exit(nullptr);
+            return 0;
+        }
+        case kContentInvalidated: {
+            skiaAndroidApp->paintIfNeeded();
+            break;
+        }
+        case kSurfaceCreated: {
+            SkASSERT(!skiaAndroidApp->fNativeWindow && message.fNativeWindow);
+            skiaAndroidApp->fNativeWindow = message.fNativeWindow;
+            auto window_android = (Window_android*)skiaAndroidApp->fWindow;
+            window_android->initDisplay(skiaAndroidApp->fNativeWindow);
+            skiaAndroidApp->paintIfNeeded();
+            break;
+        }
+        case kSurfaceChanged: {
+            SkASSERT(message.fNativeWindow == skiaAndroidApp->fNativeWindow &&
+                     message.fNativeWindow);
+            int width = ANativeWindow_getWidth(skiaAndroidApp->fNativeWindow);
+            int height = ANativeWindow_getHeight(skiaAndroidApp->fNativeWindow);
+            skiaAndroidApp->fWindow->onResize(width, height);
+            auto window_android = (Window_android*)skiaAndroidApp->fWindow;
+            window_android->setContentRect(0, 0, width, height);
+            skiaAndroidApp->paintIfNeeded();
+            break;
+        }
+        case kSurfaceDestroyed: {
+            if (skiaAndroidApp->fNativeWindow) {
+                auto window_android = (Window_android*)skiaAndroidApp->fWindow;
+                window_android->onDisplayDestroyed();
+                ANativeWindow_release(skiaAndroidApp->fNativeWindow);
+                skiaAndroidApp->fNativeWindow = nullptr;
+            }
+            break;
+        }
+        default: {
+            // do nothing
+        }
+    }
+
+    return 1;  // continue receiving callbacks
+}
+
+void* pthread_main(void* arg) {
+    SkDebugf("pthread_main begins");
+
+    auto skiaAndroidApp = (SkiaAndroidApp*)arg;
+
+    ALooper* looper = ALooper_prepare(ALOOPER_PREPARE_ALLOW_NON_CALLBACKS);
+    pipe(skiaAndroidApp->fPipes);
+    ALooper_addFd(looper, skiaAndroidApp->fPipes[0], LOOPER_ID_MESSAGEPIPE, ALOOPER_EVENT_INPUT,
+                  message_callback, skiaAndroidApp);
+
+    int ident;
+    int events;
+    struct android_poll_source* source;
+
+    skiaAndroidApp->fApp = Application::Create(0, nullptr, skiaAndroidApp);
+
+    while ((ident = ALooper_pollAll(-1, nullptr, &events, (void**)&source)) >= 0) {
+        SkDebugf("ALooper_pollAll ident=%d", ident);
+    }
+
+    return nullptr;
+}
+
+extern "C"  // extern "C" is needed for JNI (although the method itself is in C++)
+    JNIEXPORT jlong JNICALL
+    Java_org_skia_viewer_ViewerApplication_createNativeApp(JNIEnv* env, jobject activity) {
+    SkiaAndroidApp* skiaAndroidApp = new SkiaAndroidApp;
+    return (jlong)((size_t)skiaAndroidApp);
+}
+
+extern "C" JNIEXPORT void JNICALL Java_org_skia_viewer_ViewerApplication_destroyNativeApp(
+    JNIEnv* env, jobject activity, jlong handle) {
+    auto skiaAndroidApp = (SkiaAndroidApp*)handle;
+    skiaAndroidApp->postMessage(Message(kDestroyApp));
+}
+
+extern "C" JNIEXPORT void JNICALL Java_org_skia_viewer_ViewerActivity_onSurfaceCreated(
+    JNIEnv* env, jobject activity, jlong handle, jobject surface) {
+    auto skiaAndroidApp = (SkiaAndroidApp*)handle;
+    Message message(kSurfaceCreated);
+    message.fNativeWindow = ANativeWindow_fromSurface(env, surface);
+    skiaAndroidApp->postMessage(message);
+}
+
+extern "C" JNIEXPORT void JNICALL Java_org_skia_viewer_ViewerActivity_onSurfaceChanged(
+    JNIEnv* env, jobject activity, jlong handle, jobject surface) {
+    auto skiaAndroidApp = (SkiaAndroidApp*)handle;
+    Message message(kSurfaceChanged);
+    message.fNativeWindow = ANativeWindow_fromSurface(env, surface);
+    skiaAndroidApp->postMessage(message);
+}
+
+extern "C" JNIEXPORT void JNICALL Java_org_skia_viewer_ViewerActivity_onSurfaceDestroyed(
+    JNIEnv* env, jobject activity, jlong handle) {
+    auto skiaAndroidApp = (SkiaAndroidApp*)handle;
+    skiaAndroidApp->postMessage(Message(kSurfaceDestroyed));
+}
+
+}  // namespace sk_app