/**
* Copyright (c) 2012 Wireless Designs, LLC
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
package org.getlantern.firetweet.graphic;
import android.content.Context;
import android.content.res.ColorStateList;
import android.content.res.Resources;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.ColorFilter;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.Rect;
import android.graphics.Typeface;
import android.graphics.drawable.Drawable;
import android.text.Layout;
import android.text.StaticLayout;
import android.text.TextPaint;
import android.util.TypedValue;
/**
* A Drawable object that draws text. A TextDrawable accepts most of the same
* parameters that can be applied to {@link android.widget.TextView} for
* displaying and formatting text.
*
* Optionally, a {@link Path} may be supplied on which to draw the text.
*
* A TextDrawable has an intrinsic size equal to that required to draw all the
* text it has been supplied, when possible. In cases where a {@link Path} has
* been supplied, the caller must explicitly call
* {@link #setBounds(android.graphics.Rect) setBounds()} to provide the Drawable
* size based on the Path constraints.
*/
public class TextDrawable extends Drawable {
/* Platform XML constants for typeface */
private static final int SANS = 1;
private static final int SERIF = 2;
private static final int MONOSPACE = 3;
/* Resources for scaling values to the given device */
private final Resources mResources;
/* Paint to hold most drawing primitives for the text */
private final TextPaint mTextPaint;
/* Layout is used to measure and draw the text */
private StaticLayout mTextLayout;
/* Alignment of the text inside its bounds */
private Layout.Alignment mTextAlignment = Layout.Alignment.ALIGN_NORMAL;
/* Optional path on which to draw the text */
private Path mTextPath;
/* Stateful text color list */
private ColorStateList mTextColors;
/* Container for the bounds to be reported to widgets */
private final Rect mTextBounds;
/* Text string to draw */
private CharSequence mText = "";
/* Attribute lists to pull default values from the current theme */
private static final int[] themeAttributes = { android.R.attr.textAppearance };
private static final int[] appearanceAttributes = { android.R.attr.textSize, android.R.attr.typeface,
android.R.attr.textStyle, android.R.attr.textColor };
public TextDrawable(final Context context) {
super();
// Used to load and scale resource items
mResources = context.getResources();
// Definition of this drawables size
mTextBounds = new Rect();
// Paint to use for the text
mTextPaint = new TextPaint(Paint.ANTI_ALIAS_FLAG);
mTextPaint.density = mResources.getDisplayMetrics().density;
mTextPaint.setDither(true);
int textSize = 15;
ColorStateList textColor = null;
int styleIndex = -1;
int typefaceIndex = -1;
// Set default parameters from the current theme
final TypedArray a = context.getTheme().obtainStyledAttributes(themeAttributes);
final int appearanceId = a.getResourceId(0, -1);
a.recycle();
TypedArray ap = null;
if (appearanceId != -1) {
ap = context.obtainStyledAttributes(appearanceId, appearanceAttributes);
}
if (ap != null) {
for (int i = 0; i < ap.getIndexCount(); i++) {
final int attr = ap.getIndex(i);
switch (attr) {
case 0: // Text Size
textSize = a.getDimensionPixelSize(attr, textSize);
break;
case 1: // Typeface
typefaceIndex = a.getInt(attr, typefaceIndex);
break;
case 2: // Text Style
styleIndex = a.getInt(attr, styleIndex);
break;
case 3: // Text Color
textColor = a.getColorStateList(attr);
break;
default:
break;
}
}
ap.recycle();
}
setTextColor(textColor != null ? textColor : ColorStateList.valueOf(0xFF000000));
setRawTextSize(textSize);
Typeface tf = null;
switch (typefaceIndex) {
case SANS:
tf = Typeface.SANS_SERIF;
break;
case SERIF:
tf = Typeface.SERIF;
break;
case MONOSPACE:
tf = Typeface.MONOSPACE;
break;
}
setTypeface(tf, styleIndex);
}
@Override
public void draw(final Canvas canvas) {
if (mTextPath == null) {
// Allow the layout to draw the text
mTextLayout.draw(canvas);
} else {
// Draw directly on the canvas using the supplied path
canvas.drawTextOnPath(mText.toString(), mTextPath, 0, 0, mTextPaint);
}
}
@Override
public int getIntrinsicHeight() {
// Return the vertical bounds measured, or -1 if none
if (mTextBounds.isEmpty())
return -1;
else
return mTextBounds.bottom - mTextBounds.top;
}
@Override
public int getIntrinsicWidth() {
// Return the horizontal bounds measured, or -1 if none
if (mTextBounds.isEmpty())
return -1;
else
return mTextBounds.right - mTextBounds.left;
}
@Override
public int getOpacity() {
return mTextPaint.getAlpha();
}
/**
* Return the text currently being displayed
*/
public CharSequence getText() {
return mText;
}
/**
* Return the current text alignment setting
*/
public Layout.Alignment getTextAlign() {
return mTextAlignment;
}
/**
* Return the horizontal stretch factor of the text
*/
public float getTextScaleX() {
return mTextPaint.getTextScaleX();
}
/**
* Return the current text size, in pixels
*/
public float getTextSize() {
return mTextPaint.getTextSize();
}
/**
* Return the current typeface and style that the Paint using for display.
*/
public Typeface getTypeface() {
return mTextPaint.getTypeface();
}
@Override
public boolean isStateful() {
/*
* The drawable's ability to represent state is based on the text color
* list set
*/
return mTextColors.isStateful();
}
@Override
public void setAlpha(final int alpha) {
if (mTextPaint.getAlpha() != alpha) {
mTextPaint.setAlpha(alpha);
}
}
@Override
public void setColorFilter(final ColorFilter cf) {
if (mTextPaint.getColorFilter() != cf) {
mTextPaint.setColorFilter(cf);
}
}
/**
* Set the text that will be displayed
*
* @param text Text to display
*/
public void setText(CharSequence text) {
if (text == null) {
text = "";
}
mText = text;
measureContent();
}
/**
* Set the text alignment. The alignment itself is based on the text layout
* direction. For LTR text NORMAL is left aligned and OPPOSITE is right
* aligned. For RTL text, those alignments are reversed.
*
* @param align Text alignment value. Should be set to one of:
*
* {@link Layout.Alignment#ALIGN_NORMAL},
* {@link Layout.Alignment#ALIGN_NORMAL},
* {@link Layout.Alignment#ALIGN_OPPOSITE}.
*/
public void setTextAlign(final Layout.Alignment align) {
if (mTextAlignment != align) {
mTextAlignment = align;
measureContent();
}
}
/**
* Set the text color as a state list
*
* @param colorStateList ColorStateList of text colors, such as inflated
* from an R.color resource
*/
public void setTextColor(final ColorStateList colorStateList) {
mTextColors = colorStateList;
updateTextColors(getState());
}
/**
* Set a single text color for all states
*
* @param color Color value such as {@link Color#WHITE} or
* {@link Color#argb(int, int, int, int)}
*/
public void setTextColor(final int color) {
setTextColor(ColorStateList.valueOf(color));
}
/**
* Optional Path object on which to draw the text. If this is set,
* TextDrawable cannot properly measure the bounds this drawable will need.
* You must call {@link #setBounds(int, int, int, int) setBounds()} before
* applying this TextDrawable to any View.
*
* Calling this method with <code>null</code> will remove any Path currently
* attached.
*/
public void setTextPath(final Path path) {
if (mTextPath != path) {
mTextPath = path;
measureContent();
}
}
/**
* Set the horizontal stretch factor of the text
*
* @param size Text scale factor
*/
public void setTextScaleX(final float size) {
if (size != mTextPaint.getTextScaleX()) {
mTextPaint.setTextScaleX(size);
measureContent();
}
}
/**
* Set the text size. The value will be interpreted in "sp" units
*
* @param size Text size value, in sp
*/
public void setTextSize(final float size) {
setTextSize(TypedValue.COMPLEX_UNIT_SP, size);
}
/**
* Set the text size, using the supplied complex units
*
* @param unit Units for the text size, such as dp or sp
* @param size Text size value
*/
public void setTextSize(final int unit, final float size) {
final float dimension = TypedValue.applyDimension(unit, size, mResources.getDisplayMetrics());
setRawTextSize(dimension);
}
/**
* Sets the typeface and style in which the text should be displayed. Note
* that not all Typeface families actually have bold and italic variants, so
* you may need to use {@link #setTypeface(Typeface, int)} to get the
* appearance that you actually want.
*/
public void setTypeface(final Typeface tf) {
if (mTextPaint.getTypeface() != tf) {
mTextPaint.setTypeface(tf);
measureContent();
}
}
/**
* Sets the typeface and style in which the text should be displayed, and
* turns on the fake bold and italic bits in the Paint if the Typeface that
* you provided does not have all the bits in the style that you specified.
*
*/
public void setTypeface(Typeface tf, final int style) {
if (style > 0) {
if (tf == null) {
tf = Typeface.defaultFromStyle(style);
} else {
tf = Typeface.create(tf, style);
}
setTypeface(tf);
// now compute what (if any) algorithmic styling is needed
final int typefaceStyle = tf != null ? tf.getStyle() : 0;
final int need = style & ~typefaceStyle;
mTextPaint.setFakeBoldText((need & Typeface.BOLD) != 0);
mTextPaint.setTextSkewX((need & Typeface.ITALIC) != 0 ? -0.25f : 0);
} else {
mTextPaint.setFakeBoldText(false);
mTextPaint.setTextSkewX(0);
setTypeface(tf);
}
}
@Override
protected void onBoundsChange(final Rect bounds) {
// Update the internal bounds in response to any external requests
mTextBounds.set(bounds);
}
@Override
protected boolean onStateChange(final int[] state) {
// Upon state changes, grab the correct text color
return updateTextColors(state);
}
/**
* Internal method to take measurements of the current contents and apply
* the correct bounds when possible.
*/
private void measureContent() {
// If drawing to a path, we cannot measure intrinsic bounds
// We must resly on setBounds being called externally
if (mTextPath != null) {
// Clear any previous measurement
mTextLayout = null;
mTextBounds.setEmpty();
} else {
// Measure text bounds
final float desired = Layout.getDesiredWidth(mText, mTextPaint);
mTextLayout = new StaticLayout(mText, mTextPaint, (int) desired, mTextAlignment, 1.0f, 0.0f, false);
mTextBounds.set(0, 0, mTextLayout.getWidth(), mTextLayout.getHeight());
}
// We may need to be redrawn
invalidateSelf();
}
/*
* Set the text size, in raw pixels
*/
private void setRawTextSize(final float size) {
if (size != mTextPaint.getTextSize()) {
mTextPaint.setTextSize(size);
measureContent();
}
}
/**
* Internal method to apply the correct text color based on the drawable's
* state
*/
private boolean updateTextColors(final int[] stateSet) {
final int newColor = mTextColors.getColorForState(stateSet, Color.WHITE);
if (mTextPaint.getColor() != newColor) {
mTextPaint.setColor(newColor);
return true;
}
return false;
}
}