Update README.md (#559)

- Added Windows command to create the bazel-external link.
- Updated doc for newer Eclipse versions.
- Added more details for Run Configuration and updated lwjgl pathes.

gapic/README.md

@@ -1,21 +1,35 @@
 ## Setting up Eclipse to build the AGI UI
 
-1. Create the `bazel-external` link:
-   1. `ln -s $(bazel info output_base)/external bazel-external`
+1. Create the `bazel-external` link in the AGI checkout directory:
+   - Linux:  
+     `ln -s $(bazel info output_base)/external bazel-external`
+   - Windows Command Prompt:  
+     ``for /f usebackq %F in (`bazel info output_base`) do mklink /J bazel-external "%F/external"``
 2. Create and open a new Eclipse workspace.
 3. Open the Eclipse Preferences and navigate to **General** -> **Workspace** -> **Linked Resources**.
 4. Click **New...** to define a new path variable:
    1. Set the name to `GAPIC_PLATFORM_SRC`.
-   2. Set the value to the your platform's folder inside the gapic/src/platform folder of the AGI checkout.
-     e.g. `<gitroot>/gapic/src/platform/linux`
+   2. Set the value to the your platform's folder inside the gapic/src/platform folder of the AGI checkout, e.g. `<gitroot>/gapic/src/platform/<OS>`
    3. Click **OK** to create the variable.
-5. Click **OK** to dismiss the preferences dialog.
+5. Click **Apply and Close** to dismiss the preferences dialog.
 6. Run the bazel build to build all the generated code.
-7. Select **File** -> **Import** and then **General** -> **Existing Project into Workspace** and click **Next**.
+7. Select **File** -> **Import** and then **General** -> **Existing Projects into Workspace** and click **Next**.
    1. Enter the location of your AGI checkout into the root directory box.
    2. Click **Select All**. You should see a project named gapic.
    3. **IMPORTANT**: Uncheck **Copy projects into workspace**
-   4. Click "Finish".
-8. Set up Run Configurations.
-   1. In Arguments tab: give the `--gapid` flag. E.g.: `--gapid <path_to_agi>/bazel-bin/pkg`, replace `<path_to_agi>` with your local project path.
-   2. In Dependencies tab: add the lwjgl native jars. Find and add `/gapic/bazel-external/org_lwjgl_core_natives_linux/jar/lwjgl-3.2.0.jar`, `/gapic/bazel-external/org_lwjgl_opengl_natives_linux/jar/lwjgl-opengl-3.2.0.jar`. Folder name and jar name may vary based on your operating system.
+   4. Click **Finish**.
+8. Set up **Run Configurations**.
+   1. Select **Java Application**.
+   2. Press the button for a new configuration.
+   3. Choose a name, e.g. "Default".
+   4. In **Main** tab:
+      - In **Project** click **Browse**. **gapic** should be selected. Click **Ok**.
+      - In **Main class** click **Search**, select **Main - com.google.gapid** and click **Ok**.
+   5. In **Arguments** tab:
+      - In **Program arguments** give the `--gapid` flag. E.g.: `--gapid <path_to_agi>/bazel-bin/pkg`, replace `<path_to_agi>` with your AGI checkout path. Optionally add more arguments.
+   6. In **JRE** tab:
+      - If AGI should run with a different JRE than Eclipse, choose it in **Alternate JRE**. It might have to be added as **Installed JREs** first.
+   7. In **Classpath** tab:
+      - Select **User Entries** and click **Add JARs**. Select `/gapic/bazel-external/org_lwjgl_core/lwjgl-natives-<OS>.jar` for your OS and click **Ok**. Folder name and jar name may vary based on your operating system.
+      - Repeat for `/gapic/bazel-external/org_lwjgl_opengl/lwjgl-opengl-natives-<OS>.jar`.
+   8. Click **Apply** and **Run** to test the configuration.