Buttons not working at first and last index?

I am working on an application in which have two navigation button namely 'previous and next' which on tap load stories respectively. When i tap these buttons gently they work fine button when i tap next button to the last index continuously without any break then the previous button does not work or similarly when i start tapping previous button to the very first index i am unable to move forward.

Remember this only happens at the extreme cases, onClick is not called, don't know why.

My code is as follows, please help me out. Thanks in advance.

this the code of onClick, which works fine in all cases except the extreme cases, when buttons are not tapped gently.

 public void onClick(View v) {

    if (visible == true) {
        Log.e("visible", "true");
        return;
    }
    visible = true;

    try {
        Log.e("Now", "On Click");

        pDialog = new ProgressDialog(StoriesListController.this);
        pDialog.setIndeterminate(true);
        pDialog.setIcon(R.drawable.icon_small);
        pDialog.setCancelable(true);
        if (isFavoriteList == true) {
            pDialog.setMessage("Loading favorites...");
        } else {
            pDialog.setMessage("Loading data...");
        }
        pDialog.setTitle("Please wait");
        pDialog.setOnCancelListener(new OnCancelListener() {

            public void onCancel(DialogInterface arg0) {
                if (cancelableHeavyWorker != null) {
                    cancelableHeavyWorker.setHandler(null);
                }
                finish();
            }
        });
        pDialog.show();
        if (v == next) {
            if (ind < items.size() - 1) {
                ind++;
                loadAndShowNextActivity();
            }
        } else if (v == previous) {
            if (ind >开发者_StackOverflow中文版; 0) {
                ind--;
                loadAndShowNextActivity();
            }
        }
        // realeaseMemoryIfneededofStory(ind);
    } catch (Exception e) {

        Log.e("Error", "--.OnClink Message" + e.toString());
        e.printStackTrace();
    }
}

Moreover, the boolean variable "visible" is being set to false in the callback function.

The Code of Call Back Function is as follows:

private void fetchTopStoryDetailCallback(Object resultVector) {

    System.out.println("fetchTopStoryDetailCallback");
    try {
        Vector<?> v = (Vector<?>) resultVector;
        boolean completedOrFailed = ((Boolean) v.elementAt(0)).booleanValue();
        if (completedOrFailed == true) {
            boolean slideshow = ((Boolean) v.elementAt(1)).booleanValue();
            Object result = v.elementAt(2);
            String res[] = (String[]) result;

            if (slideshow) {
                if (Utils.topStorySlidesArrayList != null && Utils.topStorySlidesArrayList.size() > 0) {
                    Intent articleActivityIntent = new Intent(this, SlideShowActivity.class);
                    articleActivityIntent.putExtra("storyData", (String[]) result);
                    articleActivityIntent.putExtra("back", back);
                    articleActivityIntent.putStringArrayListExtra("sid", slideids);
                    // articleActivityIntent.putExtra("contentType", )
                    articleActivityIntent.putExtra("addkey", ADDS_KEY);
                    showActivityInContoller(articleActivityIntent);
                    hidePrgressgingDailog();

                } else {
                    hidePrgressgingDailog();
                    this.closeActivity = true;
                    showMessage("Error", "This story encounter an error while opening. Check your Internet Connection and try later");
                }

            } else {

                if (res[3] != null && (!(res[3].equalsIgnoreCase("null")) && (!res[3].equals("")))) {
                    Intent slideshowActivtyIntent = new Intent(this, ArticleActivity.class);
                    slideshowActivtyIntent.putExtra("storyData", (String[]) result);
                    slideshowActivtyIntent.putExtra("back", back);
                    slideshowActivtyIntent.putExtra("addkey", ADDS_KEY);
                    showActivityInContoller(slideshowActivtyIntent);
                    hidePrgressgingDailog();
                } else {
                    hidePrgressgingDailog();
                    this.closeActivity = true;
                    showMessage("Error", "This story encounter an error while opening. Check your Internet Connection and try later");
                }
            }

        } else {
            showMessage("Error", "This story encounter an error while opening. Check your Internet Connection and try later");
            hidePrgressgingDailog();
        }

    } catch (Exception e) {
        Log.e("StoriesController", "Message = " + e.toString());
        e.printStackTrace();
    }
    finally {visible = false; }
}

this is how visiblity of the buttons is set...!!!!

private void adjustButtonsVisibility() {

    try {
        if (items.size() == 1) {
            next.setEnabled(false);
            next.setImageResource(R.drawable.navigator_next_disable);
            previous.setEnabled(false);
               previous.setImageResource(R.drawable.navigator_previous_disable);
            //hidePrgressgingDailog();
            return;
        }
        if (ind == 0) {
            previous.setEnabled(false);
            next.setEnabled(true);
            previous.setImageResource(R.drawable.navigator_previous_disable);
            next.setImageResource(R.drawable.story_next_arrow);
            hidePrgressgingDailog();

        } else if (ind > 0 && ind < items.size() - 1) {
            previous.setEnabled(true);
            next.setEnabled(true);
            previous.setImageResource(R.drawable.story_previous_arrow);
            next.setImageResource(R.drawable.story_next_arrow);
        }
        if (ind == items.size() - 1) {
            previous.setEnabled(true);
            next.setEnabled(false);
            previous.setImageResource(R.drawable.story_previous_arrow);
            next.setImageResource(R.drawable.navigator_next_disable);
            hidePrgressgingDailog();
        }
    } catch (Exception e) {
        Log.e("Error", "--,adjustButtonsVisibility Message = " + e);
        e.printStackTrace();
    }
}

Do this

    if (ind == 0) {
        previous.setEnabled(false);
        previous.setImageResource(R.drawable.navigator_previous_disable);
        next.setImageResource(R.drawable.story_next_arrow);
        hidePrgressgingDailog();
    }
    else if (ind > 0 && ind < items.size() - 1) {
        previous.setEnabled(true);
        next.setEnabled(true);
        previous.setImageResource(R.drawable.story_previous_arrow);
        next.setImageResource(R.drawable.story_next_arrow);
    }
    else if (ind == items.size() - 1) {
        previous.setEnabled(true);
        next.setEnabled(false);
        previous.setImageResource(R.drawable.story_previous_arrow);
        next.setImageResource(R.drawable.navigator_next_disable);
        hidePrgressgingDailog();
    }