bluetooth: Implement RSSI indicator on android

chrome/android/java/src/org/chromium/chrome/browser/BluetoothChooserDialog.java

Index: chrome/android/java/src/org/chromium/chrome/browser/BluetoothChooserDialog.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/BluetoothChooserDialog.java b/chrome/android/java/src/org/chromium/chrome/browser/BluetoothChooserDialog.java
index c3bece95d76975a4215614bab331ec18decdc769..d34ae7f9e96f78aec6dfe095a8e1dedbd9f4eba9 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/BluetoothChooserDialog.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/BluetoothChooserDialog.java
@@ -46,6 +46,29 @@ public class BluetoothChooserDialog
     static final int DIALOG_FINISHED_CANCELLED = 1;
     static final int DIALOG_FINISHED_SELECTED = 2;
 
+    private static final ItemChooserDialog.ItemChooserRowIcon
+            SIGNAL_STRENGTH_ICONS[] = new ItemChooserDialog.ItemChooserRowIcon[] {
+                new ItemChooserDialog.ItemChooserRowIcon(
+                    R.drawable.ic_signal_cellular_0_bar_black_48dp,

[juncai, 2016/08/26 19:37:48]

Are the signal strength icon images added in different directory the same size?

I noticed that it needs to use different image size, for example:
//chrome/android/java/res/drawable-mdpi/account_management_incognito.png is:
40 by 40
//chrome/android/java/res/drawable-hdpi/account_management_incognito.png is:
60 by 60
//chrome/android/java/res/drawable-xhdpi/account_management_incognito.png is:
80 by 80
//chrome/android/java/res/drawable-xxhdpi/account_management_incognito.png is:
120 by 120
//chrome/android/java/res/drawable-xxxhdpi/account_management_incognito.png is:
160 by 160

The original signal icons have four different sizes: 18 by 18, 24 by 24, 36 by
36, 48 by 48, here it has five directories, so maybe can use same images for
//chrome/android/java/res/drawable-xxhdpi/ and
//chrome/android/java/res/drawable-xxxhdpi/?

[ortuno, 2016/09/12 05:11:27]

Each directory has a copy of the image in a different size:

mdpi -> 24px x 24px
hdpi -> 36px x 36px
xhdip -> 48px x 48px
...
I think account_management is an exception. The sizes of
ic_check_googblue_24dp.png are the same as or
ic_signal_cellular_0_bar_black_24dp. 
Hmm not sure what you mean? I think you might be confusing dp
(density-independent pixel) with px (pixel). All images are 24dp but have
different pixel resolution for example the one in drawable-mdpi is 24px by 24px
but the one in xxxhdpi is 96px by 96px.

[juncai, 2016/09/12 20:05:49]

ah, I see. Thanks!

+                    R.drawable.ic_signal_cellular_0_bar_white_48dp,

[juncai, 2016/08/26 19:37:48]

The filename probably doesn't need to include "48dp" if they are different
sizes, it can be something like the ones that are used on desktop:
//ui/resources/default_100_percent/common/signal_0_bar.png

[ortuno, 2016/09/12 05:11:27]

They all have the same dp so I think the name is appropriate. Also the name
helps the linter make sure the image is the right size. For example a 24dp image
in a xhdpi folder should be 48 x 48 pixels. If we were to remove the 24dp from
the name then we could accidentally add a 24 x 24 pixels image without the
linter complaining.

[juncai, 2016/09/12 20:05:49]

Acknowledged.

+                    "Signal Strengh Level: Lowest"),

[juncai, 2016/08/26 19:37:48]

typo:
s/Strengh/Strength

[ortuno, 2016/09/12 05:11:27]

Done.

+                new ItemChooserDialog.ItemChooserRowIcon(
+                    R.drawable.ic_signal_cellular_1_bar_black_48dp,
+                    R.drawable.ic_signal_cellular_1_bar_white_48dp,
+                    "Signal Strengh Level: Lower"),

[juncai, 2016/08/26 19:37:48]

How about naming them something more straightforward, like:
"Signal Strength Level: 0 bar"
"Signal Strength Level: 1 bar"
"Signal Strength Level: 2 bar"
"Signal Strength Level: 3 bar"
"Signal Strength Level: 4 bar"?

[ortuno, 2016/09/12 05:11:27]

Ahh good idea. That also reminded me to not hard code strings and to add tests.

+                new ItemChooserDialog.ItemChooserRowIcon(
+                    R.drawable.ic_signal_cellular_2_bar_black_48dp,
+                    R.drawable.ic_signal_cellular_2_bar_white_48dp,

[juncai, 2016/08/26 19:37:48]

As I understand, the black image is for item not selected yet, and white image
is for selected item.

Can you upload some screenshots to show the chooser with selected and
non-selected item?

[ortuno, 2016/09/12 05:11:27]

Done.

+                    "Signal Strengh Level: Low"),
+                new ItemChooserDialog.ItemChooserRowIcon(
+                    R.drawable.ic_signal_cellular_3_bar_black_48dp,
+                    R.drawable.ic_signal_cellular_3_bar_white_48dp,
+                    "Signal Strengh Level: Medium"),
+                new ItemChooserDialog.ItemChooserRowIcon(
+                    R.drawable.ic_signal_cellular_4_bar_black_48dp,
+                    R.drawable.ic_signal_cellular_4_bar_white_48dp,
+                    "Signal Strengh Level: High")};
+
     // The window that owns this dialog.
     final WindowAndroid mWindowAndroid;
 
@@ -337,9 +360,10 @@ public class BluetoothChooserDialog
 
     @VisibleForTesting
     @CalledByNative
-    void addOrUpdateDevice(String deviceId, String deviceName) {
-        mItemChooserDialog.addOrUpdateItem(
-                new ItemChooserDialog.ItemChooserRow(deviceId, deviceName));
+    void addOrUpdateDevice(String deviceId, String deviceName, int signalStrengthLevel) {
+        mItemChooserDialog.addOrUpdateItem(new ItemChooserDialog.ItemChooserRow(deviceId,
+                deviceName,
+                signalStrengthLevel == -1 ? null : SIGNAL_STRENGTH_ICONS[signalStrengthLevel]));

[juncai, 2016/08/26 19:37:48]

maybe add some assert to make sure |signalStrengthLevel| is 0-4 inclusively.

[ortuno, 2016/09/12 05:11:27]

Done.

     }
 
     @VisibleForTesting