Implement Mixins for Templates

Implement Mixin functionalities, which defines part of a template
layout, making it reusable in different layouts. For example, the
HeaderMixin allows setting and getting the header text via the mixin,
which allows for clients which uses multiple different layuots to
simplify their code via something like
     layout.getMixin(HeaderMixin.class).setText("Foobar");

Bug: 34163318
Test: ./gradlew connectedAndroidTest
Change-Id: I4348c8bb5b8e640b49c2be0c79c70aa85cf0ebc0

1 files changed, 73 insertions, 0 deletions

diff --git a/library/main/src/com/android/setupwizardlib/template/ColoredHeaderMixin.java b/library/main/src/com/android/setupwizardlib/template/ColoredHeaderMixin.java
new file mode 100644
index 0000000..ccc5aad
--- /dev/null
+++ b/library/main/src/com/android/setupwizardlib/template/ColoredHeaderMixin.java
@@ -0,0 +1,73 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.setupwizardlib.template;
+
+import android.content.res.ColorStateList;
+import android.content.res.TypedArray;
+import android.util.AttributeSet;
+import android.widget.TextView;
+
+import com.android.setupwizardlib.R;
+import com.android.setupwizardlib.TemplateLayout;
+
+/**
+ * A {@link Mixin} displaying a header text that can be set to different colors. This Mixin is
+ * registered to the tempalte using HeaderMixin.class, and can be retrieved using:
+ * {@code (ColoredHeaderMixin) templateLayout.getMixin(HeaderMixin.class}.
+ */
+public class ColoredHeaderMixin extends HeaderMixin {
+
+    /**
+     * {@inheritDoc}
+     */
+    public ColoredHeaderMixin(TemplateLayout layout, AttributeSet attrs, int defStyleAttr) {
+        super(layout, attrs, defStyleAttr);
+
+        final TypedArray a = layout.getContext().obtainStyledAttributes(
+                attrs, R.styleable.SuwColoredHeaderMixin, defStyleAttr, 0);
+
+        // Set the header color
+        final ColorStateList headerColor =
+                a.getColorStateList(R.styleable.SuwColoredHeaderMixin_suwHeaderColor);
+        if (headerColor != null) {
+            setColor(headerColor);
+        }
+
+        a.recycle();
+    }
+
+    /**
+     * Sets the color of the header text. This can also be set via XML using
+     * {@code app:suwHeaderColor}.
+     *
+     * @param color The text color of the header.
+     */
+    public void setColor(ColorStateList color) {
+        final TextView titleView = getTextView();
+        if (titleView != null) {
+            titleView.setTextColor(color);
+        }
+    }
+
+    /**
+     * @return The current text color of the header.
+     */
+    public ColorStateList getColor() {
+        final TextView titleView = getTextView();
+        return titleView != null ? titleView.getTextColors() : null;
+    }
+}