refactor(TextDrawable.java): add back TextDrawable.java

mastodon/src/main/java/org/joinmastodon/android/ui/utils/TextDrawable.java

@@ -0,0 +1,242 @@
+package org.joinmastodon.android.ui.utils;
+
+/*
+ * Copyright 2016 Ali Muzaffar
+ * <p/>
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * <p/>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p/>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import android.graphics.Canvas;
+import android.graphics.ColorFilter;
+import android.graphics.Paint;
+import android.graphics.PixelFormat;
+import android.graphics.Rect;
+import android.graphics.drawable.Drawable;
+import android.text.Editable;
+import android.text.TextWatcher;
+import android.widget.TextView;
+
+import java.lang.ref.WeakReference;
+
+public class TextDrawable extends Drawable implements TextWatcher {
+	private WeakReference<TextView> ref;
+	private String mText;
+	private Paint mPaint;
+	private Rect mHeightBounds;
+	private boolean mBindToViewPaint = false;
+	private float mPrevTextSize = 0;
+	private boolean mInitFitText = false;
+	private boolean mFitTextEnabled = false;
+
+	/**
+	 * Create a TextDrawable using the given paint object and string
+	 *
+	 * @param paint
+	 * @param s
+	 */
+	public TextDrawable(Paint paint, String s) {
+		mText = s;
+		mPaint = new Paint(paint);
+		mHeightBounds = new Rect();
+		init();
+	}
+
+	/**
+	 * Create a TextDrawable. This uses the given TextView to initialize paint and has initial text
+	 * that will be drawn. Initial text can also be useful for reserving space that may otherwise
+	 * not be available when setting compound drawables.
+	 *
+	 * @param tv               The TextView / EditText using to initialize this drawable
+	 * @param initialText      Optional initial text to display
+	 * @param bindToViewsText  Should this drawable mirror the text in the TextView
+	 * @param bindToViewsPaint Should this drawable mirror changes to Paint in the TextView, like textColor, typeface, alpha etc.
+	 *                         Note, this will override any changes made using setColorFilter or setAlpha.
+	 */
+	public TextDrawable(TextView tv, String initialText, boolean bindToViewsText, boolean bindToViewsPaint) {
+		this(tv.getPaint(), initialText);
+		ref = new WeakReference<>(tv);
+		if (bindToViewsText || bindToViewsPaint) {
+			if (bindToViewsText) {
+				tv.addTextChangedListener(this);
+			}
+			mBindToViewPaint = bindToViewsPaint;
+		}
+	}
+
+	/**
+	 * Create a TextDrawable. This uses the given TextView to initialize paint and the text that
+	 * will be drawn.
+	 *
+	 * @param tv               The TextView / EditText using to initialize this drawable
+	 * @param bindToViewsText  Should this drawable mirror the text in the TextView
+	 * @param bindToViewsPaint Should this drawable mirror changes to Paint in the TextView, like textColor, typeface, alpha etc.
+	 *                         Note, this will override any changes made using setColorFilter or setAlpha.
+	 */
+	public TextDrawable(TextView tv, boolean bindToViewsText, boolean bindToViewsPaint) {
+		this(tv, tv.getText().toString(), bindToViewsText, bindToViewsPaint);
+	}
+
+	/**
+	 * Use the provided TextView/EditText to initialize the drawable.
+	 * The Drawable will copy the Text and the Paint properties, however it will from that
+	 * point on be independant of the TextView.
+	 *
+	 * @param tv a TextView or EditText or any of their children.
+	 */
+	public TextDrawable(TextView tv) {
+		this(tv, false, false);
+	}
+
+	/**
+	 * Use the provided TextView/EditText to initialize the drawable.
+	 * The Drawable will copy the Paint properties, and use the provided text to initialise itself.
+	 *
+	 * @param tv a TextView or EditText or any of their children.
+	 * @param s  The String to draw
+	 */
+	public TextDrawable(TextView tv, String s) {
+		this(tv, s, false, false);
+	}
+
+	@Override
+	public void draw(Canvas canvas) {
+		if (mBindToViewPaint && ref.get() != null) {
+			Paint p = ref.get().getPaint();
+			canvas.drawText(mText, 0, getBounds().height(), p);
+		} else {
+			if (mInitFitText) {
+				fitTextAndInit();
+			}
+			canvas.drawText(mText, 0, getBounds().height(), mPaint);
+		}
+	}
+
+	@Override
+	public void setAlpha(int alpha) {
+		mPaint.setAlpha(alpha);
+	}
+
+	@Override
+	public void setColorFilter(ColorFilter colorFilter) {
+		mPaint.setColorFilter(colorFilter);
+	}
+
+	@Override
+	public int getOpacity() {
+		int alpha = mPaint.getAlpha();
+		if (alpha == 0) {
+			return PixelFormat.TRANSPARENT;
+		} else if (alpha == 255) {
+			return PixelFormat.OPAQUE;
+		} else {
+			return PixelFormat.TRANSLUCENT;
+		}
+	}
+
+	private void init() {
+		Rect bounds = getBounds();
+		//We want to use some character to determine the max height of the text.
+		//Otherwise if we draw something like "..." they will appear centered
+		//Here I'm just going to use the entire alphabet to determine max height.
+		mPaint.getTextBounds("1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz", 0, 1, mHeightBounds);
+		//This doesn't account for leading or training white spaces.
+		//mPaint.getTextBounds(mText, 0, mText.length(), bounds);
+		float width = mPaint.measureText(mText);
+		bounds.top = mHeightBounds.top;
+		bounds.bottom = mHeightBounds.bottom;
+		bounds.right = (int) width;
+		bounds.left = 0;
+		setBounds(bounds);
+	}
+
+	public void setPaint(Paint paint) {
+		mPaint = new Paint(paint);
+		//Since this can change the font used, we need to recalculate bounds.
+		if (mFitTextEnabled && !mInitFitText) {
+			fitTextAndInit();
+		} else {
+			init();
+		}
+		invalidateSelf();
+	}
+
+	public Paint getPaint() {
+		return mPaint;
+	}
+
+	public void setText(String text) {
+		mText = text;
+		//Since this can change the bounds of the text, we need to recalculate.
+		if (mFitTextEnabled && !mInitFitText) {
+			fitTextAndInit();
+		} else {
+			init();
+		}
+		invalidateSelf();
+	}
+
+	public String getText() {
+		return mText;
+	}
+
+	@Override
+	public void beforeTextChanged(CharSequence s, int start, int count, int after) {
+
+	}
+
+	@Override
+	public void onTextChanged(CharSequence s, int start, int before, int count) {
+
+	}
+
+	@Override
+	public void afterTextChanged(Editable s) {
+		setText(s.toString());
+	}
+
+	/**
+	 * Make the TextDrawable match the width of the View it's associated with.
+	 * <p/>
+	 * Note: While this option will not work if bindToViewPaint is true.
+	 *
+	 * @param fitText
+	 */
+	public void setFillText(boolean fitText) {
+		mFitTextEnabled = fitText;
+		if (fitText) {
+			mPrevTextSize = mPaint.getTextSize();
+			if (ref.get() != null) {
+				if (ref.get().getWidth() > 0) {
+					fitTextAndInit();
+				} else {
+					mInitFitText = true;
+				}
+			}
+		} else {
+			if (mPrevTextSize > 0) {
+				mPaint.setTextSize(mPrevTextSize);
+			}
+			init();
+		}
+	}
+
+	private void fitTextAndInit() {
+		float fitWidth = ref.get().getWidth();
+		float textWidth = mPaint.measureText(mText);
+		float multi = fitWidth / textWidth;
+		mPaint.setTextSize(mPaint.getTextSize() * multi);
+		mInitFitText = false;
+		init();
+	}
+
+}