Implement touch control

tools/viewer/sk_app/android/surface_glue_android.cpp

Index: tools/viewer/sk_app/android/surface_glue_android.cpp
diff --git a/tools/viewer/sk_app/android/surface_glue_android.cpp b/tools/viewer/sk_app/android/surface_glue_android.cpp
index 3d8617f0aa4ab8854991fbeb37151ff60894c840..451d71e0f7b39d8765f46f4c0290c32bd7140dab 100644
--- a/tools/viewer/sk_app/android/surface_glue_android.cpp
+++ b/tools/viewer/sk_app/android/surface_glue_android.cpp
@@ -16,6 +16,7 @@
 #include <android/keycodes.h>
 #include <android/looper.h>
 #include <android/native_window_jni.h>
+#include <android/input.h>
 
 #include "../Application.h"
 #include "SkTypes.h"
@@ -31,6 +32,13 @@ static const std::unordered_map<int, Window::Key> ANDROID_TO_WINDOW_KEYMAP({
     {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);
@@ -121,13 +129,19 @@ int SkiaAndroidApp::message_callback(int fd, int events, void* data) {
             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
         }
@@ -203,7 +217,18 @@ extern "C" JNIEXPORT void JNICALL Java_org_skia_viewer_ViewerActivity_onKeyPress
                                                                                    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.

 }