gecko/mobile/android/base/FontSizePreference.java

262 lines
12 KiB
Java

/* -*- Mode: Java; c-basic-offset: 4; tab-width: 4; indent-tabs-mode: nil; -*-
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
package org.mozilla.gecko;
import android.app.AlertDialog;
import android.content.Context;
import android.content.res.Configuration;
import android.content.res.Resources;
import android.preference.DialogPreference;
import android.preference.Preference.OnPreferenceChangeListener;
import android.text.method.ScrollingMovementMethod;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.util.Log;
import android.util.TypedValue;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewTreeObserver;
import android.view.ViewTreeObserver.OnGlobalLayoutListener;
import android.widget.Button;
import android.widget.TextView;
import java.util.HashMap;
class FontSizePreference extends DialogPreference {
private static final String LOGTAG = "FontSizePreference";
private static final int TWIP_TO_PT_RATIO = 20; // 20 twip = 1 point.
private static final int PREVIEW_FONT_SIZE_UNIT = TypedValue.COMPLEX_UNIT_PT;
private static final int DEFAULT_FONT_INDEX = 2;
// Final line height = line height * line_mult + line_mult;
private static final float LINE_SPACING_ADD = 0f; // Units unknown.
private static final float LINE_SPACING_MULT = 1.0f;
private static final float MIN_TEXTVIEW_WIDTH_DIP = 360; // Width of the Galaxy Nexus (portrait).
/** The dialog will encompass the minimum width + (1 / scaleFactor) of the remaining space. */
private static final float TEXTVIEW_WIDTH_SCALE_FACTOR = 3;
private final Context mContext;
private int mCurrentOrientation;
private TextView mPreviewFontView;
private Button mIncreaseFontButton;
private Button mDecreaseFontButton;
private final String[] mFontTwipValues;
private final String[] mFontSizeNames; // Ex: "Small".
/** Index into the above arrays for the saved preference value (from Gecko). */
private int mSavedFontIndex = DEFAULT_FONT_INDEX;
/** Index into the above arrays for the currently displayed font size (the preview). */
private int mPreviewFontIndex = mSavedFontIndex;
private final HashMap<String, Integer> mFontTwipToIndexMap;
private boolean mPreviewFontViewHeightSet;
public FontSizePreference(Context context, AttributeSet attrs) {
super(context, attrs);
mContext = context;
final Resources res = mContext.getResources();
mFontTwipValues = res.getStringArray(R.array.pref_font_size_values);
mFontSizeNames = res.getStringArray(R.array.pref_font_size_entries);
mFontTwipToIndexMap = new HashMap<String, Integer>();
for (int i = 0; i < mFontTwipValues.length; ++i) {
mFontTwipToIndexMap.put(mFontTwipValues[i], i);
}
mCurrentOrientation = res.getConfiguration().orientation;
}
@Override
protected void onPrepareDialogBuilder(AlertDialog.Builder builder) {
final LayoutInflater inflater =
(LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View dialogView = inflater.inflate(R.layout.font_size_preference, null);
mPreviewFontView = (TextView) dialogView.findViewById(R.id.preview);
mPreviewFontView.setMovementMethod(new ScrollingMovementMethod());
// There is no way to get the value for this padding so we turn it off.
mPreviewFontView.setIncludeFontPadding(false);
// Retrieving line spacing is not available until API 16 so we override the values instead.
mPreviewFontView.setLineSpacing(LINE_SPACING_ADD, LINE_SPACING_MULT);
mDecreaseFontButton = (Button) dialogView.findViewById(R.id.decrease_preview_font_button);
mIncreaseFontButton = (Button) dialogView.findViewById(R.id.increase_preview_font_button);
mDecreaseFontButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
updatePreviewFontSize(mFontTwipValues[--mPreviewFontIndex]);
mIncreaseFontButton.setEnabled(true);
// If we reached the minimum index, disable the button.
if (mPreviewFontIndex == 0) {
mDecreaseFontButton.setEnabled(false);
}
}
});
mIncreaseFontButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
updatePreviewFontSize(mFontTwipValues[++mPreviewFontIndex]);
mDecreaseFontButton.setEnabled(true);
// If we reached the maximum index, disable the button.
if (mPreviewFontIndex == mFontTwipValues.length - 1) {
mIncreaseFontButton.setEnabled(false);
}
}
});
// Set mPreviewFontView dimensions.
setPreviewFontViewWidth();
setPreviewFontViewHeightListener();
setFontSizeToMaximum(); // Expects onGlobalLayout() to be called.
builder.setView(dialogView);
}
@Override
protected void onDialogClosed(boolean positiveResult) {
super.onDialogClosed(positiveResult);
if (!positiveResult) {
mPreviewFontIndex = mSavedFontIndex;
return;
}
mSavedFontIndex = mPreviewFontIndex;
final String twipVal = mFontTwipValues[mSavedFontIndex];
final OnPreferenceChangeListener prefChangeListener = getOnPreferenceChangeListener();
if (prefChangeListener == null) {
Log.e(LOGTAG, "PreferenceChangeListener is null. FontSizePreference will not be saved to Gecko.");
return;
}
prefChangeListener.onPreferenceChange(this, twipVal);
}
protected void onConfigurationChanged(Configuration newConfig) {
if (mCurrentOrientation != newConfig.orientation) {
mCurrentOrientation = newConfig.orientation;
// mPreviewFontView will be null if the dialog has not yet been shown.
if (mPreviewFontView != null) {
// Recalculate the mPreviewFontView dimensions since we have new screen dimensions.
setPreviewFontViewWidth();
mPreviewFontViewHeightSet = false;
setFontSizeToMaximum(); // Expects onGlobalLayout() to be called.
}
}
}
/**
* Sets the preview font size to the maximum given size.
*/
private void setFontSizeToMaximum() {
updatePreviewFontSize(mFontTwipValues[mFontTwipValues.length - 1]);
// NOTE: If this method is being used with onGlobalLayout() to set mFontPreviewView height,
// the font size cannot be changed past this point or the dialog height will not calculate
// correctly. We must wait for the global layout state to change, calculate the height in
// onGlobalLayout(), and only then can changes be made.
}
/**
* Sets a global layout listener that will calculate the maximum required height of
* mPreviewFontView based upon the current font values and then reset the TextView to the saved
* preference values. This listener will only run once. mPreviewFontViewHeightSet must be set to
* false before being used again.
*/
private void setPreviewFontViewHeightListener() {
mPreviewFontViewHeightSet = false;
final ViewTreeObserver vto = mPreviewFontView.getViewTreeObserver();
vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
@Override
public void onGlobalLayout() {
if (!mPreviewFontViewHeightSet) {
mPreviewFontViewHeightSet = true;
final int desiredHeight = (int) (mPreviewFontView.getLineCount() *
mPreviewFontView.getLineHeight() * LINE_SPACING_MULT + LINE_SPACING_ADD +
mPreviewFontView.getPaddingTop() + mPreviewFontView.getPaddingBottom());
mPreviewFontView.setHeight(desiredHeight);
// Set the dialog state to the saved preference values.
setButtonState(mPreviewFontIndex);
updatePreviewFontSize(mFontTwipValues[mPreviewFontIndex]);
}
}
});
}
/**
* Sets the width of the mPreviewFontView TextView. The width is calculated by adding a constant
* minimum width to a fraction of the remaining space on screen (if any), which is determined by
* the given scale factor. Note that in ICS, it appears that the dialog will not wrap content
* and will set the view size itself. In Gingerbread, this code executes and sets the dialog
* width dynamically.
*/
private void setPreviewFontViewWidth() {
final DisplayMetrics metrics = mContext.getResources().getDisplayMetrics();
final float density = metrics.density;
final float actualWidthDip = metrics.widthPixels / density;
float scaleExtraDip = (actualWidthDip - MIN_TEXTVIEW_WIDTH_DIP) / TEXTVIEW_WIDTH_SCALE_FACTOR;
scaleExtraDip = scaleExtraDip >= 0 ? scaleExtraDip : 0;
final float desiredWidthDip = MIN_TEXTVIEW_WIDTH_DIP + scaleExtraDip;
final int desiredWidthPx = Math.round(desiredWidthDip * density);
mPreviewFontView.setWidth(desiredWidthPx);
}
/**
* Finds the index of the given twip value and sets it as the saved preference value. Also the
* current preview text size to the given value. Does not update the mPreviewFontView text size.
*/
protected void setSavedFontSize(String twip) {
final Integer index = mFontTwipToIndexMap.get(twip);
if (index != null) {
mSavedFontIndex = index;
mPreviewFontIndex = mSavedFontIndex;
return;
}
resetSavedFontSizeToDefault();
Log.e(LOGTAG, "setSavedFontSize: Given font size does not exist in twip values map. Reverted to default font size.");
}
/**
* Updates the mPreviewFontView to the given text size, resets the scroll to the top left, and
* invalidates the view. Does not update the font indices.
*/
private void updatePreviewFontSize(String twip) {
float pt = convertTwipStrToPT(twip);
// Android will not render a font size of 0 pt but for Gecko, 0 twip turns off font
// inflation. Thus we special case 0 twip to display a renderable font size.
if (pt == 0) {
mPreviewFontView.setTextSize(PREVIEW_FONT_SIZE_UNIT, 1);
} else {
mPreviewFontView.setTextSize(PREVIEW_FONT_SIZE_UNIT, pt);
}
mPreviewFontView.scrollTo(0, 0);
}
/**
* Resets the font indices to the default value. Does not update the mPreviewFontView text size.
*/
private void resetSavedFontSizeToDefault() {
mSavedFontIndex = DEFAULT_FONT_INDEX;
mPreviewFontIndex = mSavedFontIndex;
}
private void setButtonState(int index) {
if (index == 0) {
mDecreaseFontButton.setEnabled(false);
} else if (index == mFontTwipValues.length - 1) {
mIncreaseFontButton.setEnabled(false);
}
}
/**
* Returns the name of the font size (ex: "Small") at the currently saved preference value.
*/
protected String getSavedFontSizeName() {
return mFontSizeNames[mSavedFontIndex];
}
private float convertTwipStrToPT(String twip) {
return Float.parseFloat(twip) / TWIP_TO_PT_RATIO;
}
}