How to use

getPaddingTop

method

in

com.davemorrissey.labs.subscaleview.SubsamplingScaleImageView

/**
 * Given a requested source center and scale, calculate what the actual center will have to be to keep the image in
 * pan limits, keeping the requested center as near to the middle of the screen as allowed.
 */
@NonNull
private PointF limitedSCenter(float sCenterX, float sCenterY, float scale, @NonNull PointF sTarget) {
  PointF vTranslate = vTranslateForSCenter(sCenterX, sCenterY, scale);
  int vxCenter = getPaddingLeft() + (getWidth() - getPaddingRight() - getPaddingLeft())/2;
  int vyCenter = getPaddingTop() + (getHeight() - getPaddingBottom() - getPaddingTop())/2;
  float sx = (vxCenter - vTranslate.x)/scale;
  float sy = (vyCenter - vTranslate.y)/scale;
  sTarget.set(sx, sy);
  return sTarget;
}

/**
 * Get the translation required to place a given source coordinate at the center of the screen, with the center
 * adjusted for asymmetric padding. Accepts the desired scale as an argument, so this is independent of current
 * translate and scale. The result is fitted to bounds, putting the image point as near to the screen center as permitted.
 */
@NonNull
private PointF vTranslateForSCenter(float sCenterX, float sCenterY, float scale) {
  int vxCenter = getPaddingLeft() + (getWidth() - getPaddingRight() - getPaddingLeft())/2;
  int vyCenter = getPaddingTop() + (getHeight() - getPaddingBottom() - getPaddingTop())/2;
  if (satTemp == null) {
    satTemp = new ScaleAndTranslate(0, new PointF(0, 0));
  }
  satTemp.scale = scale;
  satTemp.vTranslate.set(vxCenter - (sCenterX * scale), vyCenter - (sCenterY * scale));
  fitToBounds(true, satTemp);
  return satTemp.vTranslate;
}

int vyCenter = getPaddingTop() + (getHeight() - getPaddingBottom() - getPaddingTop())/2;
float targetScale = limitedScale(this.targetScale);
PointF targetSCenter = panLimited ? limitedSCenter(this.targetSCenter.x, this.targetSCenter.y, targetScale, new PointF()) : this.targetSCenter;

float yPaddingRatio = getPaddingTop() > 0 || getPaddingBottom() > 0 ? getPaddingTop()/(float)(getPaddingTop() + getPaddingBottom()) : 0.5f;

/**
 * Returns the minimum allowed scale.
 */
private float minScale() {
  int vPadding = getPaddingBottom() + getPaddingTop();
  int hPadding = getPaddingLeft() + getPaddingRight();
  if (minimumScaleType == SCALE_TYPE_CENTER_CROP || minimumScaleType == SCALE_TYPE_START) {
    return Math.max((getWidth() - hPadding) / (float) sWidth(), (getHeight() - vPadding) / (float) sHeight());
  } else if (minimumScaleType == SCALE_TYPE_CUSTOM && minScale > 0) {
    return minScale;
  } else {
    return Math.min((getWidth() - hPadding) / (float) sWidth(), (getHeight() - vPadding) / (float) sHeight());
  }
}

/**
 * Given a requested source center and scale, calculate what the actual center will have to be to keep the image in
 * pan limits, keeping the requested center as near to the middle of the screen as allowed.
 */
private PointF limitedSCenter(float sCenterX, float sCenterY, float scale, PointF sTarget) {
  PointF vTranslate = vTranslateForSCenter(sCenterX, sCenterY, scale);
  int vxCenter = getPaddingLeft() + (getWidth() - getPaddingRight() - getPaddingLeft())/2;
  int vyCenter = getPaddingTop() + (getHeight() - getPaddingBottom() - getPaddingTop())/2;
  float sx = (vxCenter - vTranslate.x)/scale;
  float sy = (vyCenter - vTranslate.y)/scale;
  sTarget.set(sx, sy);
  return sTarget;
}

/**
 * Get the translation required to place a given source coordinate at the center of the screen, with the center
 * adjusted for asymmetric padding. Accepts the desired scale as an argument, so this is independent of current
 * translate and scale. The result is fitted to bounds, putting the image point as near to the screen center as permitted.
 */
private PointF vTranslateForSCenter(float sCenterX, float sCenterY, float scale) {
  int vxCenter = getPaddingLeft() + (getWidth() - getPaddingRight() - getPaddingLeft())/2;
  int vyCenter = getPaddingTop() + (getHeight() - getPaddingBottom() - getPaddingTop())/2;
  if (satTemp == null) {
    satTemp = new ScaleAndTranslate(0, new PointF(0, 0));
  }
  satTemp.scale = scale;
  satTemp.vTranslate.set(vxCenter - (sCenterX * scale), vyCenter - (sCenterY * scale));
  fitToBounds(true, satTemp);
  return satTemp.vTranslate;
}

int vyCenter = getPaddingTop() + (getHeight() - getPaddingBottom() - getPaddingTop())/2;
float targetScale = limitedScale(this.targetScale);
PointF targetSCenter = panLimited ? limitedSCenter(this.targetSCenter.x, this.targetSCenter.y, targetScale, new PointF()) : this.targetSCenter;

float yPaddingRatio = getPaddingTop() > 0 || getPaddingBottom() > 0 ? getPaddingTop()/(float)(getPaddingTop() + getPaddingBottom()) : 0.5f;

/**
 * Returns the minimum allowed scale.
 */
private float minScale() {
  int vPadding = getPaddingBottom() + getPaddingTop();
  int hPadding = getPaddingLeft() + getPaddingRight();
  if (minimumScaleType == SCALE_TYPE_CENTER_CROP) {
    return Math.max((getWidth() - hPadding) / (float) sWidth(), (getHeight() - vPadding) / (float) sHeight());
  } else if (minimumScaleType == SCALE_TYPE_CUSTOM && minScale > 0) {
    return minScale;
  } else {
    return Math.min((getWidth() - hPadding) / (float) sWidth(), (getHeight() - vPadding) / (float) sHeight());
  }
}