{"id":71,"date":"2011-08-13T21:52:46","date_gmt":"2011-08-14T01:52:46","guid":{"rendered":"http:\/\/robobunny.com\/wp\/?p=71"},"modified":"2011-08-13T21:52:46","modified_gmt":"2011-08-14T01:52:46","slug":"android-seekbar-preference","status":"publish","type":"post","link":"https:\/\/robobunny.com\/wp\/?p=71","title":{"rendered":"Android SeekBar preference"},"content":{"rendered":"

Attention:<\/span> This version of the SeekBar is obsolete, check out the new version instead<\/a><\/span><\/p>\n

While working on my Android implementation<\/a> of the Dislexicon<\/a>, I realized I would need a SeekBar preference to adjust the text-to-speech speed. I found a couple of SeekBar prefs online, but none of them fit my needs. Specifically, I wanted it to:<\/p>\n

    \n
  1. Appear on the main preference screen, instead of a separate window accessed via a button<\/li>\n
  2. Fill the entire width of the screen<\/li>\n
  3. Allow a minimum value other than zero<\/li>\n<\/ol>\n

    Here’s what I ended up with, as it appears in Dislexicon:<\/p>\n

    \"\"<\/a>

    SeekBar Preference<\/p><\/div>\n


    \nYou’ll need two files, plus a preferences section. They are all inline below, but you can download them here:<\/p>\n\n\n\n\n\n\n\n
    File<\/th>\n<\/th>\nDescription<\/th>\n<\/tr>\n<\/thead>\n
    preferences.xml<\/a><\/td>\n<\/td>\nExample of adding a config to your preferences.<\/td>\n<\/tr>\n
    SeekBarPreference.java<\/a><\/td>\n<\/td>\nThe java class.<\/td>\n<\/tr>\n
    seek_bar_preference.xml<\/a><\/td>\n<\/td>\nThe XML layout of the preference. This should go in your res\/layout directory.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

     <\/p>\n

    Here’s an example of configuring it in your preferences.xml file. Most of the parameters work exactly the same as a standard preference, but there are two new parameters:<\/p>\n

      \n
    1. min: Minimum value to use for the slider. The default is zero<\/li>\n
    2. units: The characters to put to the right of the value, to indicate the units (eg. %, deg, .oz)<\/li>\n<\/ol>\n

      preferences.xml<\/a>
      \n[cc lang=”xml”]
      \n<\/p>\n

      <\/p>\n

      \t
      \n\t\t
      \n\t<\/PreferenceCategory><\/p>\n

      <\/PreferenceScreen>
      \n[\/cc]<\/p>\n

      The java class itself.
      \n      SeekBarPreference.java<\/a>
      \n[cc lang=”java”]
      \npackage com.robobunny;<\/p>\n

      import android.content.Context;
      \nimport android.content.res.TypedArray;
      \nimport android.preference.Preference;
      \nimport android.util.AttributeSet;
      \nimport android.util.Log;
      \nimport android.view.LayoutInflater;
      \nimport android.view.View;
      \nimport android.view.ViewGroup;
      \nimport android.view.ViewParent;
      \nimport android.widget.RelativeLayout;
      \nimport android.widget.SeekBar;
      \nimport android.widget.SeekBar.OnSeekBarChangeListener;
      \nimport android.widget.TextView;<\/p>\n

      public class SeekBarPreference extends Preference implements OnSeekBarChangeListener {<\/p>\n

      \tprivate final String TAG = getClass().getName();<\/p>\n

      \tprivate static final String ANDROIDNS=”http:\/\/schemas.android.com\/apk\/res\/android”;
      \n\tprivate static final String ROBOBUNNYNS=”http:\/\/robobunny.com”;
      \n\tprivate static final int DEFAULT_VALUE = 50;<\/p>\n

      \tprivate int mMaxValue = 100;
      \n\tprivate int mMinValue = 0;
      \n\tprivate int mInterval = 1;
      \n\tprivate int mCurrentValue;
      \n\tprivate String mUnitsLeft = “”;
      \n\tprivate String mUnitsRight = “”;
      \n\tprivate SeekBar mSeekBar;<\/p>\n

      \tprivate TextView mStatusText;<\/p>\n

      \tpublic SeekBarPreference(Context context, AttributeSet attrs) {
      \n\t\tsuper(context, attrs);
      \n\t\tinitPreference(context, attrs);
      \n\t}<\/p>\n

      \tpublic SeekBarPreference(Context context, AttributeSet attrs, int defStyle) {
      \n\t\tsuper(context, attrs, defStyle);
      \n\t\tinitPreference(context, attrs);
      \n\t}<\/p>\n

      \tprivate void initPreference(Context context, AttributeSet attrs) {
      \n\t\tsetValuesFromXml(attrs);
      \n\t\tmSeekBar = new SeekBar(context, attrs);
      \n\t\tmSeekBar.setMax(mMaxValue – mMinValue);
      \n\t\tmSeekBar.setOnSeekBarChangeListener(this);
      \n\t}<\/p>\n

      \tprivate void setValuesFromXml(AttributeSet attrs) {
      \n\t\tmMaxValue = attrs.getAttributeIntValue(ANDROIDNS, “max”, 100);
      \n\t\tmMinValue = attrs.getAttributeIntValue(ROBOBUNNYNS, “min”, 0);<\/p>\n

      \t\tmUnitsLeft = getAttributeStringValue(attrs, ROBOBUNNYNS, “unitsLeft”, “”);
      \n\t\tString units = getAttributeStringValue(attrs, ROBOBUNNYNS, “units”, “”);
      \n\t\tmUnitsRight = getAttributeStringValue(attrs, ROBOBUNNYNS, “unitsRight”, units);<\/p>\n

      \t\ttry {
      \n\t\t\tString newInterval = attrs.getAttributeValue(ROBOBUNNYNS, “interval”);
      \n\t\t\tif(newInterval != null)
      \n\t\t\t\tmInterval = Integer.parseInt(newInterval);
      \n\t\t}
      \n\t\tcatch(Exception e) {
      \n\t\t\tLog.e(TAG, “Invalid interval value”, e);
      \n\t\t}<\/p>\n

      \t}<\/p>\n

      \tprivate String getAttributeStringValue(AttributeSet attrs, String namespace, String name, String defaultValue) {
      \n\t\tString value = attrs.getAttributeValue(namespace, name);
      \n\t\tif(value == null)
      \n\t\t\tvalue = defaultValue;<\/p>\n

      \t\treturn value;
      \n\t}<\/p>\n

      \t@Override
      \n\tprotected View onCreateView(ViewGroup parent){<\/p>\n

      \t\tRelativeLayout layout = null;<\/p>\n

      \t\ttry {
      \n\t\t\tLayoutInflater mInflater = (LayoutInflater) getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);<\/p>\n

      \t\t\tlayout = (RelativeLayout)mInflater.inflate(R.layout.seek_bar_preference, parent, false);
      \n\t\t}
      \n\t\tcatch(Exception e)
      \n\t\t{
      \n\t\t\tLog.e(TAG, “Error creating seek bar preference”, e);
      \n\t\t}<\/p>\n

      \t\treturn layout;<\/p>\n

      \t}<\/p>\n

      \t@Override
      \n\tpublic void onBindView(View view) {
      \n\t\tsuper.onBindView(view);<\/p>\n

      \t\ttry
      \n\t\t{
      \n\t\t\t\/\/ move our seekbar to the new view we’ve been given
      \n\t ViewParent oldContainer = mSeekBar.getParent();
      \n\t ViewGroup newContainer = (ViewGroup) view.findViewById(R.id.seekBarPrefBarContainer);<\/p>\n

      \t if (oldContainer != newContainer) {
      \n\t \t\/\/ remove the seekbar from the old view
      \n\t if (oldContainer != null) {
      \n\t ((ViewGroup) oldContainer).removeView(mSeekBar);
      \n\t }
      \n\t \/\/ remove the existing seekbar (there may not be one) and add ours
      \n\t newContainer.removeAllViews();
      \n\t newContainer.addView(mSeekBar, ViewGroup.LayoutParams.FILL_PARENT,
      \n\t ViewGroup.LayoutParams.WRAP_CONTENT);
      \n\t }
      \n\t\t}
      \n\t\tcatch(Exception ex) {
      \n\t\t\tLog.e(TAG, “Error binding view: ” + ex.toString());
      \n\t\t}<\/p>\n

      \t\tupdateView(view);
      \n\t}<\/p>\n

      \t\/**
      \n\t * Update a SeekBarPreference view with our current state
      \n\t * @param view
      \n\t *\/
      \n\tprotected void updateView(View view) {<\/p>\n

      \t\ttry {
      \n\t\t\tRelativeLayout layout = (RelativeLayout)view;<\/p>\n

      \t\t\tmStatusText = (TextView)layout.findViewById(R.id.seekBarPrefValue);
      \n\t\t\tmStatusText.setText(String.valueOf(mCurrentValue));
      \n\t\t\tmStatusText.setMinimumWidth(30);<\/p>\n

      \t\t\tmSeekBar.setProgress(mCurrentValue – mMinValue);<\/p>\n

      \t\t\tTextView unitsRight = (TextView)layout.findViewById(R.id.seekBarPrefUnitsRight);
      \n\t\t\tunitsRight.setText(mUnitsRight);<\/p>\n

      \t\t\tTextView unitsLeft = (TextView)layout.findViewById(R.id.seekBarPrefUnitsLeft);
      \n\t\t\tunitsLeft.setText(mUnitsLeft);<\/p>\n

      \t\t}
      \n\t\tcatch(Exception e) {
      \n\t\t\tLog.e(TAG, “Error updating seek bar preference”, e);
      \n\t\t}<\/p>\n

      \t}<\/p>\n

      \t@Override
      \n\tpublic void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
      \n\t\tint newValue = progress + mMinValue;<\/p>\n

      \t\tif(newValue > mMaxValue)
      \n\t\t\tnewValue = mMaxValue;
      \n\t\telse if(newValue < mMinValue)\n\t\t\tnewValue = mMinValue;\n\t\telse if(mInterval != 1 && newValue % mInterval != 0)\n\t\t\tnewValue = Math.round(((float)newValue)\/mInterval)*mInterval; \n\t\t\n\t\t\/\/ change rejected, revert to the previous value\n\t\tif(!callChangeListener(newValue)){\n\t\t\tseekBar.setProgress(mCurrentValue - mMinValue); \n\t\t\treturn; \n\t\t}\n\n\t\t\/\/ change accepted, store it\n\t\tmCurrentValue = newValue;\n\t\tmStatusText.setText(String.valueOf(newValue));\n\t\tpersistInt(newValue);\n\n\t}\n\n\t@Override\n\tpublic void onStartTrackingTouch(SeekBar seekBar) {}\n\n\t@Override\n\tpublic void onStopTrackingTouch(SeekBar seekBar) {\n\t\tnotifyChanged();\n\t}\n\n\n\t@Override \n\tprotected Object onGetDefaultValue(TypedArray ta, int index){\n\t\t\n\t\tint defaultValue = ta.getInt(index, DEFAULT_VALUE);\n\t\treturn defaultValue;\n\t\t\n\t}\n\n\t@Override\n\tprotected void onSetInitialValue(boolean restoreValue, Object defaultValue) {\n\n\t\tif(restoreValue) {\n\t\t\tmCurrentValue = getPersistedInt(mCurrentValue);\n\t\t}\n\t\telse {\n\t\t\tint temp = 0;\n\t\t\ttry {\n\t\t\t\ttemp = (Integer)defaultValue;\n\t\t\t}\n\t\t\tcatch(Exception ex) {\n\t\t\t\tLog.e(TAG, \"Invalid default value: \" + defaultValue.toString());\n\t\t\t}\n\t\t\t\n\t\t\tpersistInt(temp);\n\t\t\tmCurrentValue = temp;\n\t\t}\n\t\t\n\t}\n\t\n}\n[\/cc]\n\nThe preference layout file. You can use this to tweek what the preference looks like.\n      seek_bar_preference.xml<\/a>
      \n[cc lang=”xml”]
      \n<\/p>\n

      <\/p>\n

      \t<\/TextView><\/p>\n

      \t<\/TextView><\/p>\n

      \t<\/TextView><\/p>\n

      \t<\/TextView><\/p>\n

      \t<\/TextView><\/p>\n

      \t
      \n\t<\/LinearLayout><\/p>\n

      <\/RelativeLayout>
      \n[\/cc]<\/p>\n","protected":false},"excerpt":{"rendered":"

      Attention: This version of the SeekBar is obsolete, check out the new version instead While working on my Android implementation of the Dislexicon, I realized I would need a SeekBar preference to adjust the text-to-speech speed. I found a couple of SeekBar prefs online, but none of them fit my needs. Specifically, I wanted it […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[2],"tags":[13,26,28,29],"_links":{"self":[{"href":"https:\/\/robobunny.com\/wp\/index.php?rest_route=\/wp\/v2\/posts\/71"}],"collection":[{"href":"https:\/\/robobunny.com\/wp\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/robobunny.com\/wp\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/robobunny.com\/wp\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/robobunny.com\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=71"}],"version-history":[{"count":0,"href":"https:\/\/robobunny.com\/wp\/index.php?rest_route=\/wp\/v2\/posts\/71\/revisions"}],"wp:attachment":[{"href":"https:\/\/robobunny.com\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=71"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/robobunny.com\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=71"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/robobunny.com\/wp\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=71"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}