In this context "resolver" means "to issue/render a decision" and "visto para resolver" means that the case has reached a point in which the judge can proceed to issue a decision, i.e., all evidence has been taken, all witness heard, all procedural steps taken, and nothing is left except for the judge to render his decision. In English this is known (believe it or not) as being "ripe for decision" (or "ripe for judgment," in the case of "visto para sentencia.")

Here is the definition of "ripe for judgment" from Black's Law Dictionary (6th ed.).

"Ripe for judgment--an action that is so far advanced, by verdict, default, confession, the determination of all pending motions, or other disposition of preliminary or disputed matters, that nothing remains for the court but to render the appropriate judgment."

Here is the definition of "ripeness" from Black's Law Dictionary (8th ed.):

"Ripeness--1. The circumstance existing when a case has reached, but has not passed, the point when the facts have been developed sufficiently to permit an intelligent and useful decision to be made. 2. The requirement that this circumstance must exist before a court will decide a case."

Examples from the 39,400 googles for "ripe for decision":

After considering the parties’ arguments the Court concludes it lacks ... ripe for decision, the harm asserted must have matured enough to warrant judicial ...
www.baller.com/pdfs/nkc_dismissal_tw_suit.pdf

Moreover, the Court found the case was ripe for decision because it would be futile to force Palazzolo to continue to submit additional plans when the ...
www.olemiss.edu/orgs/SGLC/ National/SandBar/4.3palazzola.htm

The court stated that "to be ripe for decision a case must be fit for judicial resolution and the parties must experience hardship if the court withheld ...
www.nationalaglawcenter.org/ assets/archivecases/missourisoybeans.html

Either decision may then be appealed to the United States Court of Appeals ... favor the exercise of our discretion to consider the case ripe for decision. ...
laws.findlaw.com/us/000/02-196.html

Were the Court to rule that these regulations are not ripe for decision because they are being facially challenged, Plaintiffs could be faced with bringing ...
www.fs.fed.us/emc/applit/includes/eiivdp2.pdf

on petition for writ of certiorari to the United States Court of Appeals for ... concluded that the case was "ready and ripe" for decision, id., at 1486, ...
www.law.cornell.edu/supct/html/95-2082.ZPC.html