1 files changed, 82 insertions, 0 deletions
diff --git a/library/src/main/java/moe/yuuta/flow/NavigationBar.java b/library/src/main/java/moe/yuuta/flow/NavigationBar.java
new file mode 100644
index 0000000..14fae26
--- /dev/null
+++ b/library/src/main/java/moe/yuuta/flow/NavigationBar.java
@@ -0,0 +1,82 @@
+package moe.yuuta.flow;
+
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.Button;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
+class NavigationBar {
+    public enum ButtonPosition {
+        LEFT,
+        RIGHT
+    }
+
+    private ViewGroup mRoot;
+    private Button mLeftButton;
+    private Button mRightButton;
+
+    NavigationBar() {}
+
+    NavigationBar(@NonNull ViewGroup navBarRoot) {
+        attach(navBarRoot);
+    }
+
+    /**
+     * The config will be reset after re-attaching.
+     */
+    void attach(@NonNull ViewGroup navBarRoot) {
+        mRoot = navBarRoot;
+        mLeftButton = mRoot.findViewById(R.id.flow_nav_left_button);
+        mRightButton = mRoot.findViewById(R.id.flow_nav_right_button);
+    }
+
+    @NonNull
+    Button getButton(@NonNull ButtonPosition position) {
+        switch (position) {
+            case LEFT:
+                return mLeftButton;
+            case RIGHT:
+                return mRightButton;
+            default:
+                throw new IllegalArgumentException("Unexpected position");
+        }
+    }
+
+    private void setListener(@NonNull ButtonPosition position, @Nullable View.OnClickListener listener) {
+        switch (position) {
+            case LEFT:
+                mLeftButton.setOnClickListener(listener);
+                break;
+            case RIGHT:
+                mRightButton.setOnClickListener(listener);
+                break;
+        }
+    }
+
+    void applyInfo(@NonNull NavigationBarConfig config) {
+        mLeftButton.setText(config.getLeftButtonText());
+        mRightButton.setText(config.getRightButtonText());
+        setNavigationBarVisibility(config.getNavBarVisibility());
+        setButtonVisibility(ButtonPosition.LEFT, config.getLeftButtonVisibility());
+        setButtonVisibility(ButtonPosition.RIGHT, config.getRightButtonVisibility());
+        setListener(ButtonPosition.LEFT, config.getLeftListener());
+        setListener(ButtonPosition.RIGHT, config.getRightListener());
+    }
+
+    private void setNavigationBarVisibility(@View.Visibility int visibility) {
+        mRoot.setVisibility(visibility);
+    }
+
+    private void setButtonVisibility(@NonNull ButtonPosition position, @View.Visibility int visibility) {
+        switch (position) {
+            case LEFT:
+                mLeftButton.setVisibility(visibility);
+                break;
+            case RIGHT:
+                mRightButton.setVisibility(visibility);
+                break;
+        }
+    }
+}