[Offline pages] Adding capability to free up space used by Offline pages

chrome/android/java/src/org/chromium/chrome/browser/offline_pages/OfflinePageStorageSpaceHeader.java

Index: chrome/android/java/src/org/chromium/chrome/browser/offline_pages/OfflinePageStorageSpaceHeader.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/offline_pages/OfflinePageStorageSpaceHeader.java b/chrome/android/java/src/org/chromium/chrome/browser/offline_pages/OfflinePageStorageSpaceHeader.java
new file mode 100644
index 0000000000000000000000000000000000000000..8a29383db292c23e6c8b2207f441bdbd47665dda
--- /dev/null
+++ b/chrome/android/java/src/org/chromium/chrome/browser/offline_pages/OfflinePageStorageSpaceHeader.java
@@ -0,0 +1,94 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser.offline_pages;
+
+import android.app.Activity;
+import android.content.Context;
+import android.support.v7.widget.RecyclerView.ViewHolder;
+import android.text.format.Formatter;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.TextView;
+
+import org.chromium.chrome.R;
+
+import java.util.List;
+
+/**
+ * Header shown in saved pages view to inform user of total used storage and offer freeing up
+ * space.
+ */
+public class OfflinePageStorageSpaceHeader {
+    /**
+     * Minimal total size of all pages, before a header will be shown to offer freeing up space.
+     */
+    private static final long MINIMUM_TOTAL_SIZE_BYTES = 10 * (1 << 20); // 10MB
+    /**
+     * Minimal size of pages to clean up, before a header will be shown to offer freeing up space.
+     */
+    private static final long MINIMUM_CEALNUP_SIZE_BYTES = 5 * (1 << 20); // 5MB
+
+    OfflinePageBridge mOfflinePageBridge;
+    Context mContext;
+    OfflinePageFreeUpSpaceCallback mCallback;
+
+    /**
+     * @param offlinePageBridge An object to access offline page functionality.
+     */
+    public OfflinePageStorageSpaceHeader(Context context, OfflinePageBridge offlinePageBridge,
+            OfflinePageFreeUpSpaceCallback callback) {
+        assert offlinePageBridge != null;
+        mOfflinePageBridge = offlinePageBridge;
+        mContext = context;
+        mCallback = callback;
+    }
+
+    /** @return Whether the header should be shown. */
+    public boolean shouldShow() {
+        return getSizeOfAllPages() > MINIMUM_TOTAL_SIZE_BYTES
+                && getSizeOfPagesToCleanUp() > MINIMUM_CEALNUP_SIZE_BYTES;
+    }
+
+    /** @return A view holder with the contents of the header. */
+    public ViewHolder createHolder(ViewGroup parent) {
+        // TODO(fgorski): Enable recalculation in case some pages were deleted.
+        ViewGroup header = (ViewGroup) LayoutInflater.from(mContext).inflate(
+                R.layout.eb_offline_pages_storage_space_header, parent, false);
+
+        ((TextView) header.findViewById(R.id.storage_header_message))
+                .setText(mContext.getString(R.string.offline_pages_storage_space_message,
+                        Formatter.formatFileSize(mContext, getSizeOfAllPages())));
+
+        header.findViewById(R.id.storage_header_button)
+                .setOnClickListener(new View.OnClickListener() {
+                    @Override
+                    public void onClick(View view) {
+                        OfflinePageFreeUpSpaceDialog dialog =
+                                OfflinePageFreeUpSpaceDialog.newInstance(
+                                        mOfflinePageBridge, mCallback);
+                        dialog.show(((Activity) mContext).getFragmentManager(), null);
+                    }
+                });
+
+        return new ViewHolder(header) {};
+    }
+
+    private long getSizeOfAllPages() {
+        return getTotalSize(mOfflinePageBridge.getAllPages());
+    }
+
+    private long getSizeOfPagesToCleanUp() {
+        return getTotalSize(mOfflinePageBridge.getPagesToCleanUp());
+    }
+
+    private long getTotalSize(List<OfflinePageItem> offlinePages) {
+        long totalSize = 0;
+        for (OfflinePageItem page : offlinePages) {
+            totalSize += page.getFileSize();
+        }
+        return totalSize;
+    }
+}