Implement touch control

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 <unordered_map>
 
 #include <android/keycodes.h>
 #include <android/looper.h>
 #include <android/native_window_jni.h>
+#include <android/input.h>
 
 #include "../Application.h"
 #include "SkTypes.h"
 #include "SkUtils.h"
 #include "Window_android.h"
 
 namespace sk_app {
 
 static const int LOOPER_ID_MESSAGEPIPE = 1;
 
 static const std::unordered_map<int, Window::Key> ANDROID_TO_WINDOW_KEYMAP({
     {AKEYCODE_SOFT_LEFT, Window::Key::kLeft},
     {AKEYCODE_SOFT_RIGHT, Window::Key::kRight}
 });
 
+static const std::unordered_map<int, Window::InputState> ANDROID_TO_WINDOW_STATEMAP({
+    {AMOTION_EVENT_ACTION_DOWN, Window::kDown_InputState},
+    {AMOTION_EVENT_ACTION_UP, Window::kUp_InputState},
+    {AMOTION_EVENT_ACTION_MOVE, Window::kMove_InputState},
+    {AMOTION_EVENT_ACTION_CANCEL, Window::kUp_InputState},
+});
+
 SkiaAndroidApp::SkiaAndroidApp(JNIEnv* env, jobject androidApp) {
     env->GetJavaVM(&fJavaVM);
     fAndroidApp = env->NewGlobalRef(androidApp);
     jclass cls = env->GetObjectClass(fAndroidApp);
     fSetTitleMethodID = env->GetMethodID(cls, "setTitle", "(Ljava/lang/String;)V");
     fNativeWindow = nullptr;
     pthread_create(&fThread, nullptr, pthread_main, this);
 }
 
 SkiaAndroidApp::~SkiaAndroidApp() {
@@ skipping 70 matching lines @@
         case kSurfaceDestroyed: {
             if (skiaAndroidApp->fNativeWindow) {
                 auto window_android = (Window_android*)skiaAndroidApp->fWindow;
                 window_android->onDisplayDestroyed();
                 ANativeWindow_release(skiaAndroidApp->fNativeWindow);
                 skiaAndroidApp->fNativeWindow = nullptr;
             }
             break;
         }
         case kKeyPressed: {
-            auto it = ANDROID_TO_WINDOW_KEYMAP.find(message.keycode);
+            auto it = ANDROID_TO_WINDOW_KEYMAP.find(message.fKeycode);
             SkASSERT(it != ANDROID_TO_WINDOW_KEYMAP.end());
             // No modifier is supported so far
             skiaAndroidApp->fWindow->onKey(it->second, Window::kDown_InputState, 0);
             skiaAndroidApp->fWindow->onKey(it->second, Window::kUp_InputState, 0);
             break;
         }
+        case kTouched: {
+            auto it = ANDROID_TO_WINDOW_STATEMAP.find(message.fTouchState);
+            SkASSERT(it != ANDROID_TO_WINDOW_STATEMAP.end());
+            skiaAndroidApp->fWindow->onTouch(message.fTouchOwner, it->second, message.fTouchX, message.fTouchY);
+            break;
+        }
         default: {
             // do nothing
         }
     }
 
     return 1;  // continue receiving callbacks
 }
 
 void* SkiaAndroidApp::pthread_main(void* arg) {
     SkDebugf("pthread_main begins");
@@ skipping 55 matching lines @@
     auto skiaAndroidApp = (SkiaAndroidApp*)handle;
     skiaAndroidApp->postMessage(Message(kSurfaceDestroyed));
 }
 
 extern "C" JNIEXPORT void JNICALL Java_org_skia_viewer_ViewerActivity_onKeyPressed(JNIEnv* env,
                                                                                    jobject activity,
                                                                                    jlong handle,
                                                                                    jint keycode) {
     auto skiaAndroidApp = (SkiaAndroidApp*)handle;
     Message message(kKeyPressed);
-    message.keycode = keycode;
+    message.fKeycode = keycode;
     skiaAndroidApp->postMessage(message);
 }
 
+extern "C" JNIEXPORT void JNICALL Java_org_skia_viewer_ViewerActivity_onTouched(JNIEnv* env,
+    jobject activity, jlong handle, jint owner, jfloat x, jfloat y, jint state) {
+    auto skiaAndroidApp = (SkiaAndroidApp*)handle;
+    Message message(kTouched);
+    message.fTouchOwner = owner;
+    message.fTouchState = state;
+    message.fTouchX = x;
+    message.fTouchY = y;
+    skiaAndroidApp->postMessage(message);

[djsollen, 2016/05/16 18:16:00]

do you need to post a message for this or can you just update the SkTouchGesture
in your thread and trigger an inval if needed?

[liyuqian, 2016/05/16 18:32:37]

I tend to defer as much work as possible to my own pthread. First, I don't want
to make UI thread do too much work which might make the app less responsive.
Second (more importantly), I don't want two threads (one UI thread, one pthread)
to concurrently modify some Skia properties/canvas, which may trigger race
conditions; putting everything into our message queue is the simplest and most
efficient way to guarantee that.

+}
+
 }  // namespace sk_app