HeatMapLegendView.java

/* 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
 * 
 * http://www.apache.org/licenses/LICENSE-2.0
 * 
 * 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.
 */
package uk.ac.cam.cl.dtg.snowdon;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.view.View;

import kr.kdev.dg1s.biowiki.R;

/**
 * HeatMapLegendView is the class for a HeatMap legend. Colours are specified
 * independently from those in the HeatMap, so care must be taken to make sure
 * they agree.
 *
 * @author ajdm2
 */
public class HeatMapLegendView extends View {
    protected Paint mTextPaint = new Paint();
    protected Paint mMinPaint = new Paint();
    protected Paint mMaxPaint = new Paint();
    protected Paint mNaNPaint = new Paint();
    protected Paint mRectPaint = new Paint();
    protected String mMaxText = "max";
    protected String mMinText = "min";
    protected String mNaNText = "no data";
    protected float mTopPadding = 10.0f;

    protected String customSchemaLocation;

    /**
     * Creates a new HeatMapLegendView and sets layout parameters based on those
     * defined in XML.
     *
     * @param context
     * @param attributes
     */
    public HeatMapLegendView(Context context, AttributeSet attributes) {
        super(context, attributes);

        customSchemaLocation = getResources().getString(R.string.NS);

        mTextPaint.setColor(attributes.getAttributeIntValue(customSchemaLocation, "heat_map_legend_text_colour", 0xFF000000));
        mRectPaint.setColor(attributes.getAttributeIntValue(customSchemaLocation, "heat_map_legend_box_border_colour", 0xFF000000));
        mRectPaint.setStyle(Paint.Style.STROKE);
        mMinPaint.setColor(attributes.getAttributeIntValue(customSchemaLocation, "heat_map_legend_min_colour", 0xFFeefbff));
        mMaxPaint.setColor(attributes.getAttributeIntValue(customSchemaLocation, "heat_map_legend_max_colour", 0xFF006280));
        mNaNPaint.setColor(attributes.getAttributeIntValue(customSchemaLocation, "heat_map_legend_no_data_colour", 0xFFaeaeae));
        mTextPaint.setTextSize(attributes.getAttributeFloatValue(customSchemaLocation, "heat_map_legend_text_size", 20.0f));
        mTextPaint.setAntiAlias(attributes.getAttributeBooleanValue(customSchemaLocation, "heat_map_legend_text_anti_alias", true));
        mRectPaint.setAntiAlias(attributes.getAttributeBooleanValue(customSchemaLocation, "heat_map_legend_box_anti_alias", true));
        mMinPaint.setAntiAlias(attributes.getAttributeBooleanValue(customSchemaLocation, "heat_map_legend_box_anti_alias", true));
        mMaxPaint.setAntiAlias(attributes.getAttributeBooleanValue(customSchemaLocation, "heat_map_legend_box_anti_alias", true));
        ;
    }

    @Override
    public void onDraw(Canvas canvas) {
        int quarterOfWidth = getWidth() / 4;
        float rectWidth = 20 * getResources().getDisplayMetrics().density;

        canvas.drawText(mMinText, 1 * quarterOfWidth - mTextPaint.measureText(mMinText) / 2, mTopPadding + rectWidth + mTextPaint.getTextSize(), mTextPaint);
        canvas.drawRect(1 * quarterOfWidth - rectWidth / 2, mTopPadding, 1 * quarterOfWidth + rectWidth / 2, mTopPadding + rectWidth, mMinPaint);
        canvas.drawRect(1 * quarterOfWidth - rectWidth / 2, mTopPadding, 1 * quarterOfWidth + rectWidth / 2, mTopPadding + rectWidth, mRectPaint);

        canvas.drawText(mMaxText, 2 * quarterOfWidth - mTextPaint.measureText(mMaxText) / 2, mTopPadding + rectWidth + mTextPaint.getTextSize(), mTextPaint);
        canvas.drawRect(2 * quarterOfWidth - rectWidth / 2, mTopPadding, 2 * quarterOfWidth + rectWidth / 2, mTopPadding + rectWidth, mMaxPaint);
        canvas.drawRect(2 * quarterOfWidth - rectWidth / 2, mTopPadding, 2 * quarterOfWidth + rectWidth / 2, mTopPadding + rectWidth, mRectPaint);

        canvas.drawText(mNaNText, 3 * quarterOfWidth - mTextPaint.measureText(mNaNText) / 2, mTopPadding + rectWidth + mTextPaint.getTextSize(), mTextPaint);
        canvas.drawRect(3 * quarterOfWidth - rectWidth / 2, mTopPadding, 3 * quarterOfWidth + rectWidth / 2, mTopPadding + rectWidth, mNaNPaint);
        canvas.drawRect(3 * quarterOfWidth - rectWidth / 2, mTopPadding, 3 * quarterOfWidth + rectWidth / 2, mTopPadding + rectWidth, mRectPaint);
    }

}